Chapter 20: Addition Strategies
Learn Grade 1 mathematics from very beginner explanations through worked examples, practice, reasoning, and review.
Chapter Overview
This chapter teaches Addition Strategies with simple language, step-by-step reasoning, and original worked examples. Math words are explained in simple Grade 1 language.
Key Technical Terms
- Counting all (a Grade 1 idea used in this chapter)
- Counting on (a Grade 1 idea used in this chapter)
- Using fingers (a Grade 1 idea used in this chapter)
- Using counters (a Grade 1 idea used in this chapter)
- Using a ten frame (a Grade 1 idea used in this chapter)
- Making 10 (a Grade 1 idea used in this chapter)
- Using doubles (a Grade 1 idea used in this chapter)
- Using a number line (a Grade 1 idea used in this chapter)
- Choosing an addition strategy (a Grade 1 idea used in this chapter)
- Checking addition (a Grade 1 idea used in this chapter)
How to Learn This Chapter
Read or listen to the explanation, use objects or pictures when helpful, follow one step at a time, and try the example again before checking the answer.
20.1 Counting all
Counting all helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Beginner Note
Start with real objects, fingers, or a picture. Say the idea aloud, try one small example, and check it by counting or comparing again.
10 Worked Examples with Answers and Very-Beginner Explanations
Worked Example 1
Problem: What does Counting all mean?
- Say the topic in simple words.
- Use objects, fingers, a drawing, or a number example.
- Tell what you notice.
Very beginner explanation: Counting all helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Counting all helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Worked Example 2
Problem: Show one small example of Counting all.
- Choose small numbers or a simple shape/object.
- Make a model or drawing.
- Describe what the model shows.
Very beginner explanation: Counting all helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: A correct small model or drawing can show the meaning of Counting all.
Worked Example 3
Problem: Which tool could help with Counting all?
- Think about counters, fingers, a ten frame, number line, picture, table, or real object.
- Choose the tool that makes the idea easiest to see.
Very beginner explanation: Counting all helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Use a simple tool that lets you see and check the quantities or shapes.
Worked Example 4
Problem: How can you check your work in Counting all?
- Look at the objects, drawing, or numbers again.
- Count or compare one more time.
- Make sure the answer matches the question.
Very beginner explanation: Counting all helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Check by recounting, comparing, or using a second simple model.
Worked Example 5
Problem: Where might you use Counting all in everyday life?
- Think about toys, snacks, books, classroom objects, calendars, shapes, or money.
- Choose one situation.
- Explain how the math helps.
Very beginner explanation: Counting all helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Counting all can help with a simple everyday task such as counting, sharing, comparing, measuring, organizing, or deciding.
Worked Example 6
Problem: Count to 6. What number comes just before 6?
- Count forward until 6.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 5
Worked Example 7
Problem: Count to 12. What number comes just before 12?
- Count forward until 12.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 11
Worked Example 8
Problem: Count to 19. What number comes just before 19?
- Count forward until 19.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 18
Worked Example 9
Problem: Count to 27. What number comes just before 27?
- Count forward until 27.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 26
Worked Example 10
Problem: Count to 44. What number comes just before 44?
- Count forward until 44.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 43
Practice Exercise
Create one small question about Counting all. Show it with objects, a picture, or numbers, then check by counting or comparing again.
20.2 Counting on
Counting on helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Beginner Note
Start with real objects, fingers, or a picture. Say the idea aloud, try one small example, and check it by counting or comparing again.
10 Worked Examples with Answers and Very-Beginner Explanations
Worked Example 1
Problem: What does Counting on mean?
- Say the topic in simple words.
- Use objects, fingers, a drawing, or a number example.
- Tell what you notice.
Very beginner explanation: Counting on helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Counting on helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Worked Example 2
Problem: Show one small example of Counting on.
- Choose small numbers or a simple shape/object.
- Make a model or drawing.
- Describe what the model shows.
Very beginner explanation: Counting on helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: A correct small model or drawing can show the meaning of Counting on.
Worked Example 3
Problem: Which tool could help with Counting on?
- Think about counters, fingers, a ten frame, number line, picture, table, or real object.
- Choose the tool that makes the idea easiest to see.
Very beginner explanation: Counting on helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Use a simple tool that lets you see and check the quantities or shapes.
Worked Example 4
Problem: How can you check your work in Counting on?
- Look at the objects, drawing, or numbers again.
- Count or compare one more time.
- Make sure the answer matches the question.
Very beginner explanation: Counting on helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Check by recounting, comparing, or using a second simple model.
Worked Example 5
Problem: Where might you use Counting on in everyday life?
- Think about toys, snacks, books, classroom objects, calendars, shapes, or money.
- Choose one situation.
- Explain how the math helps.
Very beginner explanation: Counting on helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Counting on can help with a simple everyday task such as counting, sharing, comparing, measuring, organizing, or deciding.
Worked Example 6
Problem: Count to 6. What number comes just before 6?
- Count forward until 6.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 5
Worked Example 7
Problem: Count to 12. What number comes just before 12?
- Count forward until 12.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 11
Worked Example 8
Problem: Count to 19. What number comes just before 19?
- Count forward until 19.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 18
Worked Example 9
Problem: Count to 27. What number comes just before 27?
- Count forward until 27.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 26
Worked Example 10
Problem: Count to 44. What number comes just before 44?
- Count forward until 44.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 43
Practice Exercise
Create one small question about Counting on. Show it with objects, a picture, or numbers, then check by counting or comparing again.
20.3 Using fingers
Using fingers is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Beginner Note
Start with real objects, fingers, or a picture. Say the idea aloud, try one small example, and check it by counting or comparing again.
10 Worked Examples with Answers and Very-Beginner Explanations
Worked Example 1
Problem: What does Using fingers mean?
- Say the topic in simple words.
- Use objects, fingers, a drawing, or a number example.
- Tell what you notice.
Very beginner explanation: Using fingers is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Using fingers is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Worked Example 2
Problem: Show one small example of Using fingers.
- Choose small numbers or a simple shape/object.
- Make a model or drawing.
- Describe what the model shows.
Very beginner explanation: Using fingers is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: A correct small model or drawing can show the meaning of Using fingers.
Worked Example 3
Problem: Which tool could help with Using fingers?
- Think about counters, fingers, a ten frame, number line, picture, table, or real object.
- Choose the tool that makes the idea easiest to see.
Very beginner explanation: Using fingers is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Use a simple tool that lets you see and check the quantities or shapes.
Worked Example 4
Problem: How can you check your work in Using fingers?
- Look at the objects, drawing, or numbers again.
- Count or compare one more time.
- Make sure the answer matches the question.
Very beginner explanation: Using fingers is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Check by recounting, comparing, or using a second simple model.
Worked Example 5
Problem: Where might you use Using fingers in everyday life?
- Think about toys, snacks, books, classroom objects, calendars, shapes, or money.
- Choose one situation.
- Explain how the math helps.
Very beginner explanation: Using fingers is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Using fingers can help with a simple everyday task such as counting, sharing, comparing, measuring, organizing, or deciding.
Worked Example 6
Problem: Show Using fingers with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Using fingers best through concrete examples and clear words.
Answer: A correct simple example of Using fingers.
Worked Example 7
Problem: Show Using fingers with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Using fingers best through concrete examples and clear words.
Answer: A correct simple example of Using fingers.
Worked Example 8
Problem: Show Using fingers with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Using fingers best through concrete examples and clear words.
Answer: A correct simple example of Using fingers.
Worked Example 9
Problem: Show Using fingers with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Using fingers best through concrete examples and clear words.
Answer: A correct simple example of Using fingers.
Worked Example 10
Problem: Show Using fingers with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Using fingers best through concrete examples and clear words.
Answer: A correct simple example of Using fingers.
Practice Exercise
Create one small question about Using fingers. Show it with objects, a picture, or numbers, then check by counting or comparing again.
20.4 Using counters
Using counters helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Beginner Note
Start with real objects, fingers, or a picture. Say the idea aloud, try one small example, and check it by counting or comparing again.
10 Worked Examples with Answers and Very-Beginner Explanations
Worked Example 1
Problem: What does Using counters mean?
- Say the topic in simple words.
- Use objects, fingers, a drawing, or a number example.
- Tell what you notice.
Very beginner explanation: Using counters helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Using counters helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Worked Example 2
Problem: Show one small example of Using counters.
- Choose small numbers or a simple shape/object.
- Make a model or drawing.
- Describe what the model shows.
Very beginner explanation: Using counters helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: A correct small model or drawing can show the meaning of Using counters.
Worked Example 3
Problem: Which tool could help with Using counters?
- Think about counters, fingers, a ten frame, number line, picture, table, or real object.
- Choose the tool that makes the idea easiest to see.
Very beginner explanation: Using counters helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Use a simple tool that lets you see and check the quantities or shapes.
Worked Example 4
Problem: How can you check your work in Using counters?
- Look at the objects, drawing, or numbers again.
- Count or compare one more time.
- Make sure the answer matches the question.
Very beginner explanation: Using counters helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Check by recounting, comparing, or using a second simple model.
Worked Example 5
Problem: Where might you use Using counters in everyday life?
- Think about toys, snacks, books, classroom objects, calendars, shapes, or money.
- Choose one situation.
- Explain how the math helps.
Very beginner explanation: Using counters helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Using counters can help with a simple everyday task such as counting, sharing, comparing, measuring, organizing, or deciding.
Worked Example 6
Problem: Count to 6. What number comes just before 6?
- Count forward until 6.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 5
Worked Example 7
Problem: Count to 12. What number comes just before 12?
- Count forward until 12.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 11
Worked Example 8
Problem: Count to 19. What number comes just before 19?
- Count forward until 19.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 18
Worked Example 9
Problem: Count to 27. What number comes just before 27?
- Count forward until 27.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 26
Worked Example 10
Problem: Count to 44. What number comes just before 44?
- Count forward until 44.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 43
Practice Exercise
Create one small question about Using counters. Show it with objects, a picture, or numbers, then check by counting or comparing again.
20.5 Using a ten frame
Using a ten frame is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Beginner Note
Start with real objects, fingers, or a picture. Say the idea aloud, try one small example, and check it by counting or comparing again.
10 Worked Examples with Answers and Very-Beginner Explanations
Worked Example 1
Problem: What does Using a ten frame mean?
- Say the topic in simple words.
- Use objects, fingers, a drawing, or a number example.
- Tell what you notice.
Very beginner explanation: Using a ten frame is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Using a ten frame is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Worked Example 2
Problem: Show one small example of Using a ten frame.
- Choose small numbers or a simple shape/object.
- Make a model or drawing.
- Describe what the model shows.
Very beginner explanation: Using a ten frame is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: A correct small model or drawing can show the meaning of Using a ten frame.
Worked Example 3
Problem: Which tool could help with Using a ten frame?
- Think about counters, fingers, a ten frame, number line, picture, table, or real object.
- Choose the tool that makes the idea easiest to see.
Very beginner explanation: Using a ten frame is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Use a simple tool that lets you see and check the quantities or shapes.
Worked Example 4
Problem: How can you check your work in Using a ten frame?
- Look at the objects, drawing, or numbers again.
- Count or compare one more time.
- Make sure the answer matches the question.
Very beginner explanation: Using a ten frame is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Check by recounting, comparing, or using a second simple model.
Worked Example 5
Problem: Where might you use Using a ten frame in everyday life?
- Think about toys, snacks, books, classroom objects, calendars, shapes, or money.
- Choose one situation.
- Explain how the math helps.
Very beginner explanation: Using a ten frame is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Using a ten frame can help with a simple everyday task such as counting, sharing, comparing, measuring, organizing, or deciding.
Worked Example 6
Problem: Show Using a ten frame with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Using a ten frame best through concrete examples and clear words.
Answer: A correct simple example of Using a ten frame.
Worked Example 7
Problem: Show Using a ten frame with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Using a ten frame best through concrete examples and clear words.
Answer: A correct simple example of Using a ten frame.
Worked Example 8
Problem: Show Using a ten frame with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Using a ten frame best through concrete examples and clear words.
Answer: A correct simple example of Using a ten frame.
Worked Example 9
Problem: Show Using a ten frame with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Using a ten frame best through concrete examples and clear words.
Answer: A correct simple example of Using a ten frame.
Worked Example 10
Problem: Show Using a ten frame with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Using a ten frame best through concrete examples and clear words.
Answer: A correct simple example of Using a ten frame.
Practice Exercise
Create one small question about Using a ten frame. Show it with objects, a picture, or numbers, then check by counting or comparing again.
20.6 Making 10
Making 10 is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Beginner Note
Start with real objects, fingers, or a picture. Say the idea aloud, try one small example, and check it by counting or comparing again.
10 Worked Examples with Answers and Very-Beginner Explanations
Worked Example 1
Problem: What does Making 10 mean?
- Say the topic in simple words.
- Use objects, fingers, a drawing, or a number example.
- Tell what you notice.
Very beginner explanation: Making 10 is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Making 10 is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Worked Example 2
Problem: Show one small example of Making 10.
- Choose small numbers or a simple shape/object.
- Make a model or drawing.
- Describe what the model shows.
Very beginner explanation: Making 10 is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: A correct small model or drawing can show the meaning of Making 10.
Worked Example 3
Problem: Which tool could help with Making 10?
- Think about counters, fingers, a ten frame, number line, picture, table, or real object.
- Choose the tool that makes the idea easiest to see.
Very beginner explanation: Making 10 is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Use a simple tool that lets you see and check the quantities or shapes.
Worked Example 4
Problem: How can you check your work in Making 10?
- Look at the objects, drawing, or numbers again.
- Count or compare one more time.
- Make sure the answer matches the question.
Very beginner explanation: Making 10 is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Check by recounting, comparing, or using a second simple model.
Worked Example 5
Problem: Where might you use Making 10 in everyday life?
- Think about toys, snacks, books, classroom objects, calendars, shapes, or money.
- Choose one situation.
- Explain how the math helps.
Very beginner explanation: Making 10 is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Making 10 can help with a simple everyday task such as counting, sharing, comparing, measuring, organizing, or deciding.
Worked Example 6
Problem: Show Making 10 with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Making 10 best through concrete examples and clear words.
Answer: A correct simple example of Making 10.
Worked Example 7
Problem: Show Making 10 with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Making 10 best through concrete examples and clear words.
Answer: A correct simple example of Making 10.
Worked Example 8
Problem: Show Making 10 with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Making 10 best through concrete examples and clear words.
Answer: A correct simple example of Making 10.
Worked Example 9
Problem: Show Making 10 with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Making 10 best through concrete examples and clear words.
Answer: A correct simple example of Making 10.
Worked Example 10
Problem: Show Making 10 with a simple Grade 1 example.
- Use small numbers, objects, or a drawing.
- Explain what the example shows.
Very beginner explanation: Grade 1 learners understand Making 10 best through concrete examples and clear words.
Answer: A correct simple example of Making 10.
Practice Exercise
Create one small question about Making 10. Show it with objects, a picture, or numbers, then check by counting or comparing again.
20.7 Using doubles
Using doubles is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Beginner Note
Start with real objects, fingers, or a picture. Say the idea aloud, try one small example, and check it by counting or comparing again.
10 Worked Examples with Answers and Very-Beginner Explanations
Worked Example 1
Problem: What does Using doubles mean?
- Say the topic in simple words.
- Use objects, fingers, a drawing, or a number example.
- Tell what you notice.
Very beginner explanation: Using doubles is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Using doubles is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Worked Example 2
Problem: Show one small example of Using doubles.
- Choose small numbers or a simple shape/object.
- Make a model or drawing.
- Describe what the model shows.
Very beginner explanation: Using doubles is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: A correct small model or drawing can show the meaning of Using doubles.
Worked Example 3
Problem: Which tool could help with Using doubles?
- Think about counters, fingers, a ten frame, number line, picture, table, or real object.
- Choose the tool that makes the idea easiest to see.
Very beginner explanation: Using doubles is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Use a simple tool that lets you see and check the quantities or shapes.
Worked Example 4
Problem: How can you check your work in Using doubles?
- Look at the objects, drawing, or numbers again.
- Count or compare one more time.
- Make sure the answer matches the question.
Very beginner explanation: Using doubles is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Check by recounting, comparing, or using a second simple model.
Worked Example 5
Problem: Where might you use Using doubles in everyday life?
- Think about toys, snacks, books, classroom objects, calendars, shapes, or money.
- Choose one situation.
- Explain how the math helps.
Very beginner explanation: Using doubles is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Answer: Using doubles can help with a simple everyday task such as counting, sharing, comparing, measuring, organizing, or deciding.
Worked Example 6
Problem: Find 2 + 3.
- Make a group of 2.
- Add 3 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 5
Worked Example 7
Problem: Find 4 + 1.
- Make a group of 4.
- Add 1 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 5
Worked Example 8
Problem: Find 5 + 2.
- Make a group of 5.
- Add 2 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 7
Worked Example 9
Problem: Find 6 + 3.
- Make a group of 6.
- Add 3 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 9
Worked Example 10
Problem: Find 8 + 2.
- Make a group of 8.
- Add 2 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 10
Practice Exercise
Create one small question about Using doubles. Show it with objects, a picture, or numbers, then check by counting or comparing again.
20.8 Using a number line
Using a number line helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Beginner Note
Start with real objects, fingers, or a picture. Say the idea aloud, try one small example, and check it by counting or comparing again.
10 Worked Examples with Answers and Very-Beginner Explanations
Worked Example 1
Problem: What does Using a number line mean?
- Say the topic in simple words.
- Use objects, fingers, a drawing, or a number example.
- Tell what you notice.
Very beginner explanation: Using a number line helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Using a number line helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Worked Example 2
Problem: Show one small example of Using a number line.
- Choose small numbers or a simple shape/object.
- Make a model or drawing.
- Describe what the model shows.
Very beginner explanation: Using a number line helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: A correct small model or drawing can show the meaning of Using a number line.
Worked Example 3
Problem: Which tool could help with Using a number line?
- Think about counters, fingers, a ten frame, number line, picture, table, or real object.
- Choose the tool that makes the idea easiest to see.
Very beginner explanation: Using a number line helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Use a simple tool that lets you see and check the quantities or shapes.
Worked Example 4
Problem: How can you check your work in Using a number line?
- Look at the objects, drawing, or numbers again.
- Count or compare one more time.
- Make sure the answer matches the question.
Very beginner explanation: Using a number line helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Check by recounting, comparing, or using a second simple model.
Worked Example 5
Problem: Where might you use Using a number line in everyday life?
- Think about toys, snacks, books, classroom objects, calendars, shapes, or money.
- Choose one situation.
- Explain how the math helps.
Very beginner explanation: Using a number line helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Answer: Using a number line can help with a simple everyday task such as counting, sharing, comparing, measuring, organizing, or deciding.
Worked Example 6
Problem: Count to 6. What number comes just before 6?
- Count forward until 6.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 5
Worked Example 7
Problem: Count to 12. What number comes just before 12?
- Count forward until 12.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 11
Worked Example 8
Problem: Count to 19. What number comes just before 19?
- Count forward until 19.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 18
Worked Example 9
Problem: Count to 27. What number comes just before 27?
- Count forward until 27.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 26
Worked Example 10
Problem: Count to 44. What number comes just before 44?
- Count forward until 44.
- Move back one number.
Very beginner explanation: The number before is one less.
Answer: 43
Practice Exercise
Create one small question about Using a number line. Show it with objects, a picture, or numbers, then check by counting or comparing again.
20.9 Choosing an addition strategy
Choosing an addition strategy teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Beginner Note
Start with real objects, fingers, or a picture. Say the idea aloud, try one small example, and check it by counting or comparing again.
10 Worked Examples with Answers and Very-Beginner Explanations
Worked Example 1
Problem: What does Choosing an addition strategy mean?
- Say the topic in simple words.
- Use objects, fingers, a drawing, or a number example.
- Tell what you notice.
Very beginner explanation: Choosing an addition strategy teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Answer: Choosing an addition strategy teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Worked Example 2
Problem: Show one small example of Choosing an addition strategy.
- Choose small numbers or a simple shape/object.
- Make a model or drawing.
- Describe what the model shows.
Very beginner explanation: Choosing an addition strategy teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Answer: A correct small model or drawing can show the meaning of Choosing an addition strategy.
Worked Example 3
Problem: Which tool could help with Choosing an addition strategy?
- Think about counters, fingers, a ten frame, number line, picture, table, or real object.
- Choose the tool that makes the idea easiest to see.
Very beginner explanation: Choosing an addition strategy teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Answer: Use a simple tool that lets you see and check the quantities or shapes.
Worked Example 4
Problem: How can you check your work in Choosing an addition strategy?
- Look at the objects, drawing, or numbers again.
- Count or compare one more time.
- Make sure the answer matches the question.
Very beginner explanation: Choosing an addition strategy teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Answer: Check by recounting, comparing, or using a second simple model.
Worked Example 5
Problem: Where might you use Choosing an addition strategy in everyday life?
- Think about toys, snacks, books, classroom objects, calendars, shapes, or money.
- Choose one situation.
- Explain how the math helps.
Very beginner explanation: Choosing an addition strategy teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Answer: Choosing an addition strategy can help with a simple everyday task such as counting, sharing, comparing, measuring, organizing, or deciding.
Worked Example 6
Problem: Find 2 + 3.
- Make a group of 2.
- Add 3 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 5
Worked Example 7
Problem: Find 4 + 1.
- Make a group of 4.
- Add 1 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 5
Worked Example 8
Problem: Find 5 + 2.
- Make a group of 5.
- Add 2 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 7
Worked Example 9
Problem: Find 6 + 3.
- Make a group of 6.
- Add 3 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 9
Worked Example 10
Problem: Find 8 + 2.
- Make a group of 8.
- Add 2 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 10
Practice Exercise
Create one small question about Choosing an addition strategy. Show it with objects, a picture, or numbers, then check by counting or comparing again.
20.10 Checking addition
Checking addition teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Beginner Note
Start with real objects, fingers, or a picture. Say the idea aloud, try one small example, and check it by counting or comparing again.
10 Worked Examples with Answers and Very-Beginner Explanations
Worked Example 1
Problem: What does Checking addition mean?
- Say the topic in simple words.
- Use objects, fingers, a drawing, or a number example.
- Tell what you notice.
Very beginner explanation: Checking addition teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Answer: Checking addition teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Worked Example 2
Problem: Show one small example of Checking addition.
- Choose small numbers or a simple shape/object.
- Make a model or drawing.
- Describe what the model shows.
Very beginner explanation: Checking addition teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Answer: A correct small model or drawing can show the meaning of Checking addition.
Worked Example 3
Problem: Which tool could help with Checking addition?
- Think about counters, fingers, a ten frame, number line, picture, table, or real object.
- Choose the tool that makes the idea easiest to see.
Very beginner explanation: Checking addition teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Answer: Use a simple tool that lets you see and check the quantities or shapes.
Worked Example 4
Problem: How can you check your work in Checking addition?
- Look at the objects, drawing, or numbers again.
- Count or compare one more time.
- Make sure the answer matches the question.
Very beginner explanation: Checking addition teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Answer: Check by recounting, comparing, or using a second simple model.
Worked Example 5
Problem: Where might you use Checking addition in everyday life?
- Think about toys, snacks, books, classroom objects, calendars, shapes, or money.
- Choose one situation.
- Explain how the math helps.
Very beginner explanation: Checking addition teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Answer: Checking addition can help with a simple everyday task such as counting, sharing, comparing, measuring, organizing, or deciding.
Worked Example 6
Problem: Find 2 + 3.
- Make a group of 2.
- Add 3 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 5
Worked Example 7
Problem: Find 4 + 1.
- Make a group of 4.
- Add 1 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 5
Worked Example 8
Problem: Find 5 + 2.
- Make a group of 5.
- Add 2 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 7
Worked Example 9
Problem: Find 6 + 3.
- Make a group of 6.
- Add 3 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 9
Worked Example 10
Problem: Find 8 + 2.
- Make a group of 8.
- Add 2 more.
- Count all the objects.
Very beginner explanation: Addition puts quantities together.
Answer: 10
Practice Exercise
Create one small question about Checking addition. Show it with objects, a picture, or numbers, then check by counting or comparing again.
Chapter Notes, Practice, and Common Mistakes
Chapter Notes
- Read or listen to the question before solving.
- Use objects, a drawing, ten frame, number line, table, graph, or simple number sentence when useful.
- Explain your thinking and check by counting, comparing, or using another simple model.
Extra Practice
- Create and solve one original problem about Counting all.
- Create and solve one original problem about Counting on.
- Create and solve one original problem about Using fingers.
- Create and solve one original problem about Using counters.
- Create and solve one original problem about Using a ten frame.
- Create and solve one original problem about Making 10.
Common Mistakes
- Skipping the meaning and trying to memorize a rule only.
- Using the wrong operation because the question was not read completely.
- Ignoring units, labels, place values, or the context of the problem.
- Not estimating or checking whether the final answer is reasonable.
30 Review Questions and Answers
Q1. What is the main idea in Counting all?
Answer: Counting all helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Q2. What is the main idea in Counting on?
Answer: Counting on helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Q3. What is the main idea in Using fingers?
Answer: Using fingers is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Q4. What is the main idea in Using counters?
Answer: Using counters helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Q5. What is the main idea in Using a ten frame?
Answer: Using a ten frame is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Q6. What is the main idea in Making 10?
Answer: Making 10 is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Q7. What is the main idea in Using doubles?
Answer: Using doubles is a Grade 1 mathematics idea. Learn it with objects or pictures first, then explain it with numbers or words.
Q8. What is the main idea in Using a number line?
Answer: Using a number line helps Grade 1 learners build strong number sense with small numbers, objects, drawings, and number lines.
Q9. What is the main idea in Choosing an addition strategy?
Answer: Choosing an addition strategy teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Q10. What is the main idea in Checking addition?
Answer: Checking addition teaches how to put quantities together. Learners use objects, drawings, ten frames, and counting-on strategies before writing number sentences.
Q11. Why is it useful to use counters or drawings?
Answer: They make the quantities visible and help you understand before using only numbers.
Q12. Why should you count carefully?
Answer: Careful counting means each object is counted once and no object is missed.
Q13. What can you do if a problem feels hard?
Answer: Use smaller numbers, draw a picture, use objects, and solve one small step at a time.
Q14. Why should both sides of an equals sign match?
Answer: The equals sign means the two sides have the same value.
Q15. How can a number line help?
Answer: It shows number order and can help you count forward or backward.
Q16. How can a ten frame help?
Answer: It organizes objects into groups that make numbers and addition easier to see.
Q17. Why are equal shares important?
Answer: Equal shares make fair groups or equal parts.
Q18. How do patterns help us predict?
Answer: A pattern rule tells us what should come next.
Q19. Why do we label a graph or table?
Answer: Labels tell us what the information represents.
Q20. How can you describe a shape?
Answer: Talk about its sides, corners, flat or curved surfaces, and other visible attributes.
Q21. How can you compare two objects?
Answer: Choose one attribute, such as length, mass, or capacity, and compare that same attribute.
Q22. Why is a calendar useful?
Answer: It organizes days, weeks, months, dates, and events.
Q23. Why does money have different values?
Answer: Different coins and bills represent different amounts of money.
Q24. Why should you explain your answer?
Answer: Explaining shows how you thought about the problem and helps you check your reasoning.
Q25. What should you do after a mistake?
Answer: Look at the step again, fix it, and try a similar example.
Q26. How can you be a confident math learner?
Answer: Use positive self-talk, try a strategy, ask questions, and remember that mistakes help you learn.
Q27. When should you use a picture?
Answer: Use a picture when it helps you see quantities, shapes, positions, or a story problem.
Q28. When should you use objects?
Answer: Use objects when you want to count, join, take away, share, sort, or compare in a hands-on way.
Q29. How can you check addition?
Answer: Recount the combined objects or use another model.
Q30. How can you check subtraction?
Answer: Put the taken-away part and the part left back together to see if they make the starting amount.