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Elapsed time between two clock times · 8 practice problems

3.MD.A.12.MD.C.7

Generated variants — 8

Freshly produced from the archetype’s parameters — problem, figure, and solution derived together.

Variant 1 answer: 1 hour 20 minutes

A workout started at 1:20 and ended at 2:40. How long did the workout take, in hours and minutes?

Show solution

Understand

A workout began at 1:20 and ended at 2:40. Find how long it lasted, in hours and minutes.

Givens

Start time is 1:20.
End time is 2:40.
The figure shows a start clock at 1:20, an end clock at 2:40, and a time band below split into 10-minute cells from 1:20 to 2:40.

Unknowns

The elapsed time from 1:20 to 2:40 in hours and minutes.

Constraints

End time is later than start time on the same afternoon.

Plan

#1 Draw a Diagram · also uses: #7 Identify Subproblems

Use the time band as a number line: jump whole hours first, then count the remaining minutes. Adding the two parts gives the total elapsed time.

Execute

#1 Draw a Diagram 3.MD.A.1

From 1:20 to 2:20 is exactly 1 hour.

1{:}20 \to 2{:}20 = 1 \text{ hour}}

Moving the hour and keeping the same minutes is a clean whole-hour hop on the time line.

#7 Identify Subproblems 2.MD.C.7

From 2:20 to 2:40 the minute hand moves 20 minutes.

2{:}20 \to 2{:}40 = 20 \text{ minutes}

After the whole-hour hops, count the remaining minutes on the time band.

#7 Identify Subproblems 3.MD.A.1

Total elapsed time is 1 hour 20 minutes.

1 \text{ hour}} + 20 \text{ minutes} = 1 hour 20 minutes

Combining the whole-hour jumps and the minute jump gives the full duration.

Answer: 1 hour 20 minutes

Review

Check by adding the duration back to the start: 1:20 plus 1 hour 20 minutes gives 2:40, which matches the end time. So 1 hour 20 minutes is correct.

Count in 10-minute cells on the time band: from 1:20 to 2:40 there are 80 minutes total = 1 hour 20 minutes.

Standards · min grade 3

3.MD.A.1 Tell and write time to the nearest minute and solve elapsed time problems — Finding the elapsed time from 1:20 to 2:40 by adding whole-hour jumps and a minute jump.
2.MD.C.7 Tell and write time from analog and digital clocks to nearest five minutes — Reading the start and end clock times and counting minutes.

💡 Hop the whole hours, then count the extra minutes: easy Grade 3 elapsed-time counting!

Variant 2 answer: 1 hour 40 minutes

A workout started at 3:10 and ended at 4:50. How long did the workout take, in hours and minutes?

Show solution

Understand

A workout began at 3:10 and ended at 4:50. Find how long it lasted, in hours and minutes.

Givens

Start time is 3:10.
End time is 4:50.
The figure shows a start clock at 3:10, an end clock at 4:50, and a time band below split into 10-minute cells from 3:10 to 4:50.

Unknowns

The elapsed time from 3:10 to 4:50 in hours and minutes.

Constraints

End time is later than start time on the same afternoon.

Plan

#1 Draw a Diagram · also uses: #7 Identify Subproblems

Use the time band as a number line: jump whole hours first, then count the remaining minutes. Adding the two parts gives the total elapsed time.

Execute

#1 Draw a Diagram 3.MD.A.1

From 3:10 to 4:10 is exactly 1 hour.

3{:}10 \to 4{:}10 = 1 \text{ hour}}

Moving the hour and keeping the same minutes is a clean whole-hour hop on the time line.

#7 Identify Subproblems 2.MD.C.7

From 4:10 to 4:50 the minute hand moves 40 minutes.

4{:}10 \to 4{:}50 = 40 \text{ minutes}

After the whole-hour hops, count the remaining minutes on the time band.

#7 Identify Subproblems 3.MD.A.1

Total elapsed time is 1 hour 40 minutes.

1 \text{ hour}} + 40 \text{ minutes} = 1 hour 40 minutes

Combining the whole-hour jumps and the minute jump gives the full duration.

Answer: 1 hour 40 minutes

Review

Check by adding the duration back to the start: 3:10 plus 1 hour 40 minutes gives 4:50, which matches the end time. So 1 hour 40 minutes is correct.

Count in 10-minute cells on the time band: from 3:10 to 4:50 there are 100 minutes total = 1 hour 40 minutes.

Standards · min grade 3

3.MD.A.1 Tell and write time to the nearest minute and solve elapsed time problems — Finding the elapsed time from 3:10 to 4:50 by adding whole-hour jumps and a minute jump.
2.MD.C.7 Tell and write time from analog and digital clocks to nearest five minutes — Reading the start and end clock times and counting minutes.

💡 Hop the whole hours, then count the extra minutes: easy Grade 3 elapsed-time counting!

Variant 3 answer: 1 hour 0 minutes

A workout started at 10:25 and ended at 11:25. How long did the workout take, in hours and minutes?

Show solution

Understand

A workout began at 10:25 and ended at 11:25. Find how long it lasted, in hours and minutes.

Givens

Start time is 10:25.
End time is 11:25.
The figure shows a start clock at 10:25, an end clock at 11:25, and a time band below split into 10-minute cells from 10:25 to 11:25.

Unknowns

The elapsed time from 10:25 to 11:25 in hours and minutes.

Constraints

End time is later than start time on the same afternoon.

Plan

#1 Draw a Diagram · also uses: #7 Identify Subproblems

Use the time band as a number line: jump whole hours first, then count the remaining minutes. Adding the two parts gives the total elapsed time.

Execute

#1 Draw a Diagram 3.MD.A.1

From 10:25 to 11:25 is exactly 1 hour.

10{:}25 \to 11{:}25 = 1 \text{ hour}}

Moving the hour and keeping the same minutes is a clean whole-hour hop on the time line.

#7 Identify Subproblems 2.MD.C.7

From 11:25 to 11:25 the minute hand moves 0 minutes.

11{:}25 \to 11{:}25 = 0 \text{ minutes}

After the whole-hour hops, count the remaining minutes on the time band.

#7 Identify Subproblems 3.MD.A.1

Total elapsed time is 1 hour 0 minutes.

1 \text{ hour}} + 0 \text{ minutes} = 1 hour 0 minutes

Combining the whole-hour jumps and the minute jump gives the full duration.

Answer: 1 hour 0 minutes

Review

Check by adding the duration back to the start: 10:25 plus 1 hour 0 minutes gives 11:25, which matches the end time. So 1 hour 0 minutes is correct.

Count in 10-minute cells on the time band: from 10:25 to 11:25 there are 60 minutes total = 1 hour 0 minutes.

Standards · min grade 3

3.MD.A.1 Tell and write time to the nearest minute and solve elapsed time problems — Finding the elapsed time from 10:25 to 11:25 by adding whole-hour jumps and a minute jump.
2.MD.C.7 Tell and write time from analog and digital clocks to nearest five minutes — Reading the start and end clock times and counting minutes.

💡 Hop the whole hours, then count the extra minutes: easy Grade 3 elapsed-time counting!

Variant 4 answer: 1 hour 30 minutes

A workout started at 9:05 and ended at 10:35. How long did the workout take, in hours and minutes?

Show solution

Understand

A workout began at 9:05 and ended at 10:35. Find how long it lasted, in hours and minutes.

Givens

Start time is 9:05.
End time is 10:35.
The figure shows a start clock at 9:05, an end clock at 10:35, and a time band below split into 10-minute cells from 9:05 to 10:35.

Unknowns

The elapsed time from 9:05 to 10:35 in hours and minutes.

Constraints

End time is later than start time on the same afternoon.

Plan

#1 Draw a Diagram · also uses: #7 Identify Subproblems

Use the time band as a number line: jump whole hours first, then count the remaining minutes. Adding the two parts gives the total elapsed time.

Execute

#1 Draw a Diagram 3.MD.A.1

From 9:05 to 10:05 is exactly 1 hour.

9{:}05 \to 10{:}05 = 1 \text{ hour}}

Moving the hour and keeping the same minutes is a clean whole-hour hop on the time line.

#7 Identify Subproblems 2.MD.C.7

From 10:05 to 10:35 the minute hand moves 30 minutes.

10{:}05 \to 10{:}35 = 30 \text{ minutes}

After the whole-hour hops, count the remaining minutes on the time band.

#7 Identify Subproblems 3.MD.A.1

Total elapsed time is 1 hour 30 minutes.

1 \text{ hour}} + 30 \text{ minutes} = 1 hour 30 minutes

Combining the whole-hour jumps and the minute jump gives the full duration.

Answer: 1 hour 30 minutes

Review

Check by adding the duration back to the start: 9:05 plus 1 hour 30 minutes gives 10:35, which matches the end time. So 1 hour 30 minutes is correct.

Count in 10-minute cells on the time band: from 9:05 to 10:35 there are 90 minutes total = 1 hour 30 minutes.

Standards · min grade 3

3.MD.A.1 Tell and write time to the nearest minute and solve elapsed time problems — Finding the elapsed time from 9:05 to 10:35 by adding whole-hour jumps and a minute jump.
2.MD.C.7 Tell and write time from analog and digital clocks to nearest five minutes — Reading the start and end clock times and counting minutes.

💡 Hop the whole hours, then count the extra minutes: easy Grade 3 elapsed-time counting!

Variant 5 answer: 1 hour 30 minutes

A workout started at 12:15 and ended at 1:45. How long did the workout take, in hours and minutes?

Show solution

Understand

A workout began at 12:15 and ended at 1:45. Find how long it lasted, in hours and minutes.

Givens

Start time is 12:15.
End time is 1:45.
The figure shows a start clock at 12:15, an end clock at 1:45, and a time band below split into 10-minute cells from 12:15 to 1:45.

Unknowns

The elapsed time from 12:15 to 1:45 in hours and minutes.

Constraints

End time is later than start time on the same afternoon.

Plan

#1 Draw a Diagram · also uses: #7 Identify Subproblems

Use the time band as a number line: jump whole hours first, then count the remaining minutes. Adding the two parts gives the total elapsed time.

Execute

#1 Draw a Diagram 3.MD.A.1

From 12:15 to 1:15 is exactly 1 hour.

12{:}15 \to 1{:}15 = 1 \text{ hour}}

Moving the hour and keeping the same minutes is a clean whole-hour hop on the time line.

#7 Identify Subproblems 2.MD.C.7

From 1:15 to 1:45 the minute hand moves 30 minutes.

1{:}15 \to 1{:}45 = 30 \text{ minutes}

After the whole-hour hops, count the remaining minutes on the time band.

#7 Identify Subproblems 3.MD.A.1

Total elapsed time is 1 hour 30 minutes.

1 \text{ hour}} + 30 \text{ minutes} = 1 hour 30 minutes

Combining the whole-hour jumps and the minute jump gives the full duration.

Answer: 1 hour 30 minutes

Review

Check by adding the duration back to the start: 12:15 plus 1 hour 30 minutes gives 1:45, which matches the end time. So 1 hour 30 minutes is correct.

Count in 10-minute cells on the time band: from 12:15 to 1:45 there are 90 minutes total = 1 hour 30 minutes.

Standards · min grade 3

3.MD.A.1 Tell and write time to the nearest minute and solve elapsed time problems — Finding the elapsed time from 12:15 to 1:45 by adding whole-hour jumps and a minute jump.
2.MD.C.7 Tell and write time from analog and digital clocks to nearest five minutes — Reading the start and end clock times and counting minutes.

💡 Hop the whole hours, then count the extra minutes: easy Grade 3 elapsed-time counting!

Variant 6 answer: 1 hour 30 minutes

A workout started at 2:45 and ended at 4:15. How long did the workout take, in hours and minutes?

Show solution

Understand

A workout began at 2:45 and ended at 4:15. Find how long it lasted, in hours and minutes.

Givens

Start time is 2:45.
End time is 4:15.
The figure shows a start clock at 2:45, an end clock at 4:15, and a time band below split into 10-minute cells from 2:45 to 4:15.

Unknowns

The elapsed time from 2:45 to 4:15 in hours and minutes.

Constraints

End time is later than start time on the same afternoon.

Plan

#1 Draw a Diagram · also uses: #7 Identify Subproblems

Use the time band as a number line: jump whole hours first, then count the remaining minutes. Adding the two parts gives the total elapsed time.

Execute

#1 Draw a Diagram 3.MD.A.1

From 2:45 to 3:45 is exactly 1 hour.

2{:}45 \to 3{:}45 = 1 \text{ hour}}

Moving the hour and keeping the same minutes is a clean whole-hour hop on the time line.

#7 Identify Subproblems 2.MD.C.7

From 3:45 to 4:15 the minute hand moves 30 minutes.

3{:}45 \to 4{:}15 = 30 \text{ minutes}

After the whole-hour hops, count the remaining minutes on the time band.

#7 Identify Subproblems 3.MD.A.1

Total elapsed time is 1 hour 30 minutes.

1 \text{ hour}} + 30 \text{ minutes} = 1 hour 30 minutes

Combining the whole-hour jumps and the minute jump gives the full duration.

Answer: 1 hour 30 minutes

Review

Check by adding the duration back to the start: 2:45 plus 1 hour 30 minutes gives 4:15, which matches the end time. So 1 hour 30 minutes is correct.

Count in 10-minute cells on the time band: from 2:45 to 4:15 there are 90 minutes total = 1 hour 30 minutes.

Standards · min grade 3

3.MD.A.1 Tell and write time to the nearest minute and solve elapsed time problems — Finding the elapsed time from 2:45 to 4:15 by adding whole-hour jumps and a minute jump.
2.MD.C.7 Tell and write time from analog and digital clocks to nearest five minutes — Reading the start and end clock times and counting minutes.

💡 Hop the whole hours, then count the extra minutes: easy Grade 3 elapsed-time counting!

Variant 7 answer: 1 hour 30 minutes

A workout started at 5:50 and ended at 7:20. How long did the workout take, in hours and minutes?

Show solution

Understand

A workout began at 5:50 and ended at 7:20. Find how long it lasted, in hours and minutes.

Givens

Start time is 5:50.
End time is 7:20.
The figure shows a start clock at 5:50, an end clock at 7:20, and a time band below split into 10-minute cells from 5:50 to 7:20.

Unknowns

The elapsed time from 5:50 to 7:20 in hours and minutes.

Constraints

End time is later than start time on the same afternoon.

Plan

#1 Draw a Diagram · also uses: #7 Identify Subproblems

Use the time band as a number line: jump whole hours first, then count the remaining minutes. Adding the two parts gives the total elapsed time.

Execute

#1 Draw a Diagram 3.MD.A.1

From 5:50 to 6:50 is exactly 1 hour.

5{:}50 \to 6{:}50 = 1 \text{ hour}}

Moving the hour and keeping the same minutes is a clean whole-hour hop on the time line.

#7 Identify Subproblems 2.MD.C.7

From 6:50 to 7:20 the minute hand moves 30 minutes.

6{:}50 \to 7{:}20 = 30 \text{ minutes}

After the whole-hour hops, count the remaining minutes on the time band.

#7 Identify Subproblems 3.MD.A.1

Total elapsed time is 1 hour 30 minutes.

1 \text{ hour}} + 30 \text{ minutes} = 1 hour 30 minutes

Combining the whole-hour jumps and the minute jump gives the full duration.

Answer: 1 hour 30 minutes

Review

Check by adding the duration back to the start: 5:50 plus 1 hour 30 minutes gives 7:20, which matches the end time. So 1 hour 30 minutes is correct.

Count in 10-minute cells on the time band: from 5:50 to 7:20 there are 90 minutes total = 1 hour 30 minutes.

Standards · min grade 3

3.MD.A.1 Tell and write time to the nearest minute and solve elapsed time problems — Finding the elapsed time from 5:50 to 7:20 by adding whole-hour jumps and a minute jump.
2.MD.C.7 Tell and write time from analog and digital clocks to nearest five minutes — Reading the start and end clock times and counting minutes.

💡 Hop the whole hours, then count the extra minutes: easy Grade 3 elapsed-time counting!

Variant 8 answer: 1 hour 30 minutes

A workout started at 7:00 and ended at 8:30. How long did the workout take, in hours and minutes?

Show solution

Understand

A workout began at 7:00 and ended at 8:30. Find how long it lasted, in hours and minutes.

Givens

Start time is 7:00.
End time is 8:30.
The figure shows a start clock at 7:00, an end clock at 8:30, and a time band below split into 10-minute cells from 7:00 to 8:30.

Unknowns

The elapsed time from 7:00 to 8:30 in hours and minutes.

Constraints

End time is later than start time on the same afternoon.

Plan

#1 Draw a Diagram · also uses: #7 Identify Subproblems

Use the time band as a number line: jump whole hours first, then count the remaining minutes. Adding the two parts gives the total elapsed time.

Execute

#1 Draw a Diagram 3.MD.A.1

From 7:00 to 8:00 is exactly 1 hour.

7{:}00 \to 8{:}00 = 1 \text{ hour}}

Moving the hour and keeping the same minutes is a clean whole-hour hop on the time line.

#7 Identify Subproblems 2.MD.C.7

From 8:00 to 8:30 the minute hand moves 30 minutes.

8{:}00 \to 8{:}30 = 30 \text{ minutes}

After the whole-hour hops, count the remaining minutes on the time band.

#7 Identify Subproblems 3.MD.A.1

Total elapsed time is 1 hour 30 minutes.

1 \text{ hour}} + 30 \text{ minutes} = 1 hour 30 minutes

Combining the whole-hour jumps and the minute jump gives the full duration.

Answer: 1 hour 30 minutes

Review

Check by adding the duration back to the start: 7:00 plus 1 hour 30 minutes gives 8:30, which matches the end time. So 1 hour 30 minutes is correct.

Count in 10-minute cells on the time band: from 7:00 to 8:30 there are 90 minutes total = 1 hour 30 minutes.

Standards · min grade 3

3.MD.A.1 Tell and write time to the nearest minute and solve elapsed time problems — Finding the elapsed time from 7:00 to 8:30 by adding whole-hour jumps and a minute jump.
2.MD.C.7 Tell and write time from analog and digital clocks to nearest five minutes — Reading the start and end clock times and counting minutes.

💡 Hop the whole hours, then count the extra minutes: easy Grade 3 elapsed-time counting!