Practice 1
From 11:45 a.m. to 12:20 p.m. on the same day, how many minutes pass?
Answer and teaching response
35 · Fifteen minutes reach noon and twenty more reach 12:20.
Count elapsed minutes across an hour boundary
Use forward jumps to connect two clock times and explain why an hour changes after sixty minutes.
Get the student and teacher materialsPrepare the group
Learning goal: A learner can calculate a same-day time interval in minutes and check it by adding the interval to the starting time.
You will need: Pencil, paper and an optional demonstration clock. All times in this workshop are on the same morning or afternoon unless stated otherwise.
Start with this question
A reading session starts at 9:35 a.m. and ends at 10:10 a.m. How long does it last?
35 minutes: 25 minutes from 9:35 to 10:00, then 10 more minutes to 10:10.
- Name the start and finish and confirm they are on the same morning. A clock reading is a position in time; elapsed time is the interval between two readings.
- Move forward to the next whole hour. There are 60 minutes in an hour, so 60 − 35 = 25 minutes reach 10:00.
- Move from 10:00 to 10:10, which adds another 10 minutes. Combine the jumps: 25 + 10 = 35.
- Check by starting at 9:35 and adding 35 minutes. Break the interval at 10:00 and confirm that the final reading is 10:10.
Run the 15-minute workshop
- 3 minutes. Identify the start and finish on a clock and ask learners to estimate whether the interval is less than an hour.
- 4 minutes. Build the two forward jumps and label each duration in minutes.
- 5 minutes. Solve the practice by drawing a line and marking any crossed hour boundary.
- 3 minutes. Use the independent check, then add the answer to the starting reading to verify the finish.
A useful error to discuss
A learner might say: Subtract 9.35 from 10.10 as if the clock readings were decimal numbers.
The digits after the colon count minutes, and 60 minutes make an hour. A decimal subtraction would use groups of one hundred, so it would describe a different system.
Practise, then check independently
Use the first three tasks for guided practice. Try the final task without help. Record a drawing or equation as well as the answer.
Practice 2
A session runs from 2:18 p.m. to 2:52 p.m. How many minutes does it last?
Answer and teaching response
34 · Both readings are in the same hour, so subtract the minute counts.
Practice 3
A workshop runs from 10:50 a.m. to 11:15 a.m. Find its duration in minutes.
Answer and teaching response
25 · Ten minutes reach 11:00, followed by fifteen more.
Independent check
A walk begins at 3:47 p.m. and ends at 4:26 p.m. How many minutes pass? Draw jumps to support your answer.
Answer and teaching response
39 · Thirteen minutes reach 4:00 and twenty-six more reach 4:26.
Transfer the idea
A task starts at 1:50 p.m. and lasts 25 minutes. What time does it finish, and how can you check?
Discuss a possible response
It finishes at 2:15 p.m. Ten minutes reach 2:00 and the remaining fifteen reach 2:15. Counting back confirms the 25-minute interval.
Choose the next teaching step
Look for:
- Distinguishes clock readings from durations.
- Uses sixty minutes per hour and labels every jump.
If the idea is not secure: Draw the next whole hour first, then fill in the minutes needed to reach it.
If the learner is ready: Solve the same interval using one large jump followed by a correction, and explain why it agrees with the split jumps.
Materials for your group
Student pages and teacher answers are separate. Download an HTML file to keep or use your browser to print or save as PDF.