Chapter 57: Elapsed Time
Learn Grade 2 mathematics with very-beginner explanations, original worked examples, practice, reasoning, and review.
Chapter Overview
This chapter teaches Elapsed Time with simple explanations, visual thinking, worked examples, practice, and review.
57.1 Meaning of elapsed time
Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end. Use objects, drawings, number lines, tables, or number sentences when useful.
10 Worked Examples with Answers
Worked Example 1
Problem: An activity starts at 9:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 10:00
Worked Example 2
Problem: An activity starts at 4:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 5:00
Worked Example 3
Problem: An activity starts at 1:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 1:30
Worked Example 4
Problem: An activity starts at 2:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 2:30
Worked Example 5
Problem: An activity starts at 8:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 9:00
Worked Example 6
Problem: An activity starts at 6:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 6:30
Worked Example 7
Problem: An activity starts at 6:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 6:30
Worked Example 8
Problem: An activity starts at 10:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 11:00
Worked Example 9
Problem: An activity starts at 6:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 7:00
Worked Example 10
Problem: An activity starts at 2:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:00
57.2 Finding elapsed hours
Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end. Use objects, drawings, number lines, tables, or number sentences when useful.
10 Worked Examples with Answers
Worked Example 1
Problem: An activity starts at 7:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 8:00
Worked Example 2
Problem: An activity starts at 1:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 1:30
Worked Example 3
Problem: An activity starts at 6:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 7:00
Worked Example 4
Problem: An activity starts at 6:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 7:00
Worked Example 5
Problem: An activity starts at 8:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 9:00
Worked Example 6
Problem: An activity starts at 3:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:30
Worked Example 7
Problem: An activity starts at 2:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:00
Worked Example 8
Problem: An activity starts at 7:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 7:30
Worked Example 9
Problem: An activity starts at 7:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 8:00
Worked Example 10
Problem: An activity starts at 4:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 4:30
57.3 Finding elapsed half hours
Fractions begin with fair sharing. Equal parts must be the same size, and equal parts can be joined to make a whole. Use objects, drawings, number lines, tables, or number sentences when useful.
10 Worked Examples with Answers
Worked Example 1
Problem: 12 objects are shared equally among 3 people. How many does each person get?
- Make equal groups.
- Share until all objects are used.
- Check that every group is equal.
Very beginner explanation: Fair sharing creates equal groups.
Answer: 4
Worked Example 2
Problem: 6 objects are shared equally among 3 people. How many does each person get?
- Make equal groups.
- Share until all objects are used.
- Check that every group is equal.
Very beginner explanation: Fair sharing creates equal groups.
Answer: 2
Worked Example 3
Problem: 16 objects are shared equally among 4 people. How many does each person get?
- Make equal groups.
- Share until all objects are used.
- Check that every group is equal.
Very beginner explanation: Fair sharing creates equal groups.
Answer: 4
Worked Example 4
Problem: 8 objects are shared equally among 4 people. How many does each person get?
- Make equal groups.
- Share until all objects are used.
- Check that every group is equal.
Very beginner explanation: Fair sharing creates equal groups.
Answer: 2
Worked Example 5
Problem: 16 objects are shared equally among 4 people. How many does each person get?
- Make equal groups.
- Share until all objects are used.
- Check that every group is equal.
Very beginner explanation: Fair sharing creates equal groups.
Answer: 4
Worked Example 6
Problem: 8 objects are shared equally among 2 people. How many does each person get?
- Make equal groups.
- Share until all objects are used.
- Check that every group is equal.
Very beginner explanation: Fair sharing creates equal groups.
Answer: 4
Worked Example 7
Problem: 8 objects are shared equally among 4 people. How many does each person get?
- Make equal groups.
- Share until all objects are used.
- Check that every group is equal.
Very beginner explanation: Fair sharing creates equal groups.
Answer: 2
Worked Example 8
Problem: 8 objects are shared equally among 4 people. How many does each person get?
- Make equal groups.
- Share until all objects are used.
- Check that every group is equal.
Very beginner explanation: Fair sharing creates equal groups.
Answer: 2
Worked Example 9
Problem: 8 objects are shared equally among 2 people. How many does each person get?
- Make equal groups.
- Share until all objects are used.
- Check that every group is equal.
Very beginner explanation: Fair sharing creates equal groups.
Answer: 4
Worked Example 10
Problem: 12 objects are shared equally among 3 people. How many does each person get?
- Make equal groups.
- Share until all objects are used.
- Check that every group is equal.
Very beginner explanation: Fair sharing creates equal groups.
Answer: 4
57.4 Finding elapsed quarter hours
Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end. Use objects, drawings, number lines, tables, or number sentences when useful.
10 Worked Examples with Answers
Worked Example 1
Problem: An activity starts at 1:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 1:30
Worked Example 2
Problem: An activity starts at 1:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 2:00
Worked Example 3
Problem: An activity starts at 10:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 10:30
Worked Example 4
Problem: An activity starts at 5:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 5:30
Worked Example 5
Problem: An activity starts at 1:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 1:30
Worked Example 6
Problem: An activity starts at 5:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 5:30
Worked Example 7
Problem: An activity starts at 3:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 4:00
Worked Example 8
Problem: An activity starts at 7:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 8:00
Worked Example 9
Problem: An activity starts at 2:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:00
Worked Example 10
Problem: An activity starts at 4:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 5:00
57.5 Using a timeline
Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end. Use objects, drawings, number lines, tables, or number sentences when useful.
10 Worked Examples with Answers
Worked Example 1
Problem: An activity starts at 9:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 10:00
Worked Example 2
Problem: An activity starts at 5:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 5:30
Worked Example 3
Problem: An activity starts at 8:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 8:30
Worked Example 4
Problem: An activity starts at 8:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 8:30
Worked Example 5
Problem: An activity starts at 10:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 11:00
Worked Example 6
Problem: An activity starts at 1:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 2:00
Worked Example 7
Problem: An activity starts at 9:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 10:00
Worked Example 8
Problem: An activity starts at 1:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 2:00
Worked Example 9
Problem: An activity starts at 3:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:30
Worked Example 10
Problem: An activity starts at 2:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:00
57.6 Start time
Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end. Use objects, drawings, number lines, tables, or number sentences when useful.
10 Worked Examples with Answers
Worked Example 1
Problem: An activity starts at 9:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 10:00
Worked Example 2
Problem: An activity starts at 5:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 6:00
Worked Example 3
Problem: An activity starts at 4:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 5:00
Worked Example 4
Problem: An activity starts at 1:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 1:30
Worked Example 5
Problem: An activity starts at 10:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 11:00
Worked Example 6
Problem: An activity starts at 8:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 8:30
Worked Example 7
Problem: An activity starts at 5:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 5:30
Worked Example 8
Problem: An activity starts at 4:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 4:30
Worked Example 9
Problem: An activity starts at 2:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:00
Worked Example 10
Problem: An activity starts at 10:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 10:30
57.7 End time
Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end. Use objects, drawings, number lines, tables, or number sentences when useful.
10 Worked Examples with Answers
Worked Example 1
Problem: An activity starts at 1:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 1:30
Worked Example 2
Problem: An activity starts at 4:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 4:30
Worked Example 3
Problem: An activity starts at 3:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 4:00
Worked Example 4
Problem: An activity starts at 1:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 2:00
Worked Example 5
Problem: An activity starts at 2:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:00
Worked Example 6
Problem: An activity starts at 1:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 1:30
Worked Example 7
Problem: An activity starts at 4:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 5:00
Worked Example 8
Problem: An activity starts at 5:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 5:30
Worked Example 9
Problem: An activity starts at 8:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 8:30
Worked Example 10
Problem: An activity starts at 6:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 6:30
57.8 Finding a missing start time
Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end. Use objects, drawings, number lines, tables, or number sentences when useful.
10 Worked Examples with Answers
Worked Example 1
Problem: An activity starts at 2:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:00
Worked Example 2
Problem: An activity starts at 7:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 8:00
Worked Example 3
Problem: An activity starts at 5:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 6:00
Worked Example 4
Problem: An activity starts at 9:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 9:30
Worked Example 5
Problem: An activity starts at 6:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 7:00
Worked Example 6
Problem: An activity starts at 1:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 1:30
Worked Example 7
Problem: An activity starts at 1:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 2:00
Worked Example 8
Problem: An activity starts at 10:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 10:30
Worked Example 9
Problem: An activity starts at 10:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 11:00
Worked Example 10
Problem: An activity starts at 4:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 4:30
57.9 Finding a missing end time
Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end. Use objects, drawings, number lines, tables, or number sentences when useful.
10 Worked Examples with Answers
Worked Example 1
Problem: An activity starts at 2:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:00
Worked Example 2
Problem: An activity starts at 3:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:30
Worked Example 3
Problem: An activity starts at 10:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 11:00
Worked Example 4
Problem: An activity starts at 2:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 2:30
Worked Example 5
Problem: An activity starts at 4:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 5:00
Worked Example 6
Problem: An activity starts at 1:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 2:00
Worked Example 7
Problem: An activity starts at 7:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 8:00
Worked Example 8
Problem: An activity starts at 8:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 8:30
Worked Example 9
Problem: An activity starts at 6:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 7:00
Worked Example 10
Problem: An activity starts at 8:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 9:00
57.10 Comparing durations
Comparing durations is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words. Use objects, drawings, number lines, tables, or number sentences when useful.
10 Worked Examples with Answers
Worked Example 1
Problem: Use 1 and 10 to make a simple example about Comparing durations.
- Recall the topic meaning.
- Use objects, a drawing, or a number sentence.
- Check that the example matches the idea.
Very beginner explanation: Simple models make Grade 2 ideas easier to understand.
Answer: A correct Grade 2 example of Comparing durations.
Worked Example 2
Problem: Use 13 and 7 to make a simple example about Comparing durations.
- Recall the topic meaning.
- Use objects, a drawing, or a number sentence.
- Check that the example matches the idea.
Very beginner explanation: Simple models make Grade 2 ideas easier to understand.
Answer: A correct Grade 2 example of Comparing durations.
Worked Example 3
Problem: Use 8 and 17 to make a simple example about Comparing durations.
- Recall the topic meaning.
- Use objects, a drawing, or a number sentence.
- Check that the example matches the idea.
Very beginner explanation: Simple models make Grade 2 ideas easier to understand.
Answer: A correct Grade 2 example of Comparing durations.
Worked Example 4
Problem: Use 16 and 12 to make a simple example about Comparing durations.
- Recall the topic meaning.
- Use objects, a drawing, or a number sentence.
- Check that the example matches the idea.
Very beginner explanation: Simple models make Grade 2 ideas easier to understand.
Answer: A correct Grade 2 example of Comparing durations.
Worked Example 5
Problem: Use 16 and 3 to make a simple example about Comparing durations.
- Recall the topic meaning.
- Use objects, a drawing, or a number sentence.
- Check that the example matches the idea.
Very beginner explanation: Simple models make Grade 2 ideas easier to understand.
Answer: A correct Grade 2 example of Comparing durations.
Worked Example 6
Problem: Use 4 and 19 to make a simple example about Comparing durations.
- Recall the topic meaning.
- Use objects, a drawing, or a number sentence.
- Check that the example matches the idea.
Very beginner explanation: Simple models make Grade 2 ideas easier to understand.
Answer: A correct Grade 2 example of Comparing durations.
Worked Example 7
Problem: Use 11 and 6 to make a simple example about Comparing durations.
- Recall the topic meaning.
- Use objects, a drawing, or a number sentence.
- Check that the example matches the idea.
Very beginner explanation: Simple models make Grade 2 ideas easier to understand.
Answer: A correct Grade 2 example of Comparing durations.
Worked Example 8
Problem: Use 19 and 11 to make a simple example about Comparing durations.
- Recall the topic meaning.
- Use objects, a drawing, or a number sentence.
- Check that the example matches the idea.
Very beginner explanation: Simple models make Grade 2 ideas easier to understand.
Answer: A correct Grade 2 example of Comparing durations.
Worked Example 9
Problem: Use 9 and 16 to make a simple example about Comparing durations.
- Recall the topic meaning.
- Use objects, a drawing, or a number sentence.
- Check that the example matches the idea.
Very beginner explanation: Simple models make Grade 2 ideas easier to understand.
Answer: A correct Grade 2 example of Comparing durations.
Worked Example 10
Problem: Use 10 and 17 to make a simple example about Comparing durations.
- Recall the topic meaning.
- Use objects, a drawing, or a number sentence.
- Check that the example matches the idea.
Very beginner explanation: Simple models make Grade 2 ideas easier to understand.
Answer: A correct Grade 2 example of Comparing durations.
57.11 Using a timer
Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end. Use objects, drawings, number lines, tables, or number sentences when useful.
10 Worked Examples with Answers
Worked Example 1
Problem: An activity starts at 9:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 9:30
Worked Example 2
Problem: An activity starts at 1:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 2:00
Worked Example 3
Problem: An activity starts at 10:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 11:00
Worked Example 4
Problem: An activity starts at 4:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 5:00
Worked Example 5
Problem: An activity starts at 8:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 8:30
Worked Example 6
Problem: An activity starts at 6:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 7:00
Worked Example 7
Problem: An activity starts at 10:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 10:30
Worked Example 8
Problem: An activity starts at 8:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 9:00
Worked Example 9
Problem: An activity starts at 7:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 8:00
Worked Example 10
Problem: An activity starts at 2:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:00
57.12 Real-life elapsed-time problems
Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end. Use objects, drawings, number lines, tables, or number sentences when useful.
10 Worked Examples with Answers
Worked Example 1
Problem: An activity starts at 5:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 5:30
Worked Example 2
Problem: An activity starts at 10:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 10:30
Worked Example 3
Problem: An activity starts at 3:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 4:00
Worked Example 4
Problem: An activity starts at 3:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 4:00
Worked Example 5
Problem: An activity starts at 3:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:30
Worked Example 6
Problem: An activity starts at 3:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 3:30
Worked Example 7
Problem: An activity starts at 6:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 7:00
Worked Example 8
Problem: An activity starts at 9:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 10:00
Worked Example 9
Problem: An activity starts at 8:00 and lasts 60 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 9:00
Worked Example 10
Problem: An activity starts at 4:00 and lasts 30 minutes. When does it end?
- Move forward by the elapsed time.
Very beginner explanation: Elapsed time tells how long passes.
Answer: 4:30
30 Review Questions and Answers
Q1. What should a Grade 2 learner understand about Meaning of elapsed time?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q2. What should a Grade 2 learner understand about Finding elapsed hours?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q3. What should a Grade 2 learner understand about Finding elapsed half hours?
Answer: Fractions begin with fair sharing. Equal parts must be the same size, and equal parts can be joined to make a whole.
Q4. What should a Grade 2 learner understand about Finding elapsed quarter hours?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q5. What should a Grade 2 learner understand about Using a timeline?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q6. What should a Grade 2 learner understand about Start time?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q7. What should a Grade 2 learner understand about End time?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q8. What should a Grade 2 learner understand about Finding a missing start time?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q9. What should a Grade 2 learner understand about Finding a missing end time?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q10. What should a Grade 2 learner understand about Comparing durations?
Answer: Comparing durations is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.
Q11. What should a Grade 2 learner understand about Using a timer?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q12. What should a Grade 2 learner understand about Real-life elapsed-time problems?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q13. What should a Grade 2 learner understand about Meaning of elapsed time?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q14. What should a Grade 2 learner understand about Finding elapsed hours?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q15. What should a Grade 2 learner understand about Finding elapsed half hours?
Answer: Fractions begin with fair sharing. Equal parts must be the same size, and equal parts can be joined to make a whole.
Q16. What should a Grade 2 learner understand about Finding elapsed quarter hours?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q17. What should a Grade 2 learner understand about Using a timeline?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q18. What should a Grade 2 learner understand about Start time?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q19. What should a Grade 2 learner understand about End time?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q20. What should a Grade 2 learner understand about Finding a missing start time?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q21. What should a Grade 2 learner understand about Finding a missing end time?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q22. What should a Grade 2 learner understand about Comparing durations?
Answer: Comparing durations is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.
Q23. What should a Grade 2 learner understand about Using a timer?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q24. What should a Grade 2 learner understand about Real-life elapsed-time problems?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q25. What should a Grade 2 learner understand about Meaning of elapsed time?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q26. What should a Grade 2 learner understand about Finding elapsed hours?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q27. What should a Grade 2 learner understand about Finding elapsed half hours?
Answer: Fractions begin with fair sharing. Equal parts must be the same size, and equal parts can be joined to make a whole.
Q28. What should a Grade 2 learner understand about Finding elapsed quarter hours?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q29. What should a Grade 2 learner understand about Using a timeline?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.
Q30. What should a Grade 2 learner understand about Start time?
Answer: Time is read with clocks and calendars. Elapsed time tells how long passes between a start and an end.