Start with a familiar journey
Imagine leaving home for the library at 3:40 pm and arriving at 4:15 pm that same afternoon. Ask your child, “How long did the journey take?” This is an original activity you can try on paper; it does not describe a reported family experience.
Elapsed time means the duration between the start and finish of an event — here, how long the journey took. The start and finish are clock times, while the answer will be a number of minutes. The Mathematics Hub Year 4 planning tool explains duration using start and end times. Its Year 4 family guidance also suggests discussing departure times for school, appointments and events.
Check the starting points
Before drawing anything, ask your child to identify the start time, the finish time and the next whole hour after 3:40 pm. The answers are 3:40 pm, 4:15 pm and 4:00 pm.
Remind them that one hour contains 60 minutes, as described in the Year 4 time and duration guidance. For this activity, your child only needs to read the digital times, count forward within 60 and add two small minute amounts. An analogue clock and decimal conversion are not required.
Split the journey at the next whole hour
Write three labelled points on the paper:
| Start | Checkpoint | Finish |
|---|---|---|
| 3:40 pm | 4:00 pm | 4:15 pm |
Draw a forward jump from 3:40 pm to 4:00 pm and label it 20 minutes. Draw another from 4:00 pm to 4:15 pm and label it 15 minutes. If the drawing is schematic rather than proportional, mark it “not to scale”.
Now combine the two intervals: 20 + 15 = 35 minutes. The journey took 35 minutes.
The 4:00 pm point is only a calculation checkpoint. It does not mean anyone stopped travelling. Counting forward through a whole hour is adapted here into a simpler Year 4 example from a bridging approach demonstrated in the NSW Department of Education’s Teaching Measurement Stage 4 resource. NSW Stage 4 is not the same as Year 4, and this is one possible strategy rather than the only correct method.
Separate clock times from durations
Point to 3:40 pm and call it a clock time: it names when the journey began. Then point to 35 minutes and call it a duration: it describes how long the journey took.
Clock notation is not decimal notation. In 3:40 pm, the 40 records minutes past 3 o’clock; it does not mean forty hundredths of an hour. Time reaches the next hour after 60 minutes, so subtracting clock labels as though they were decimal numbers will not calculate this journey correctly. The Mathematics Hub planning tool notes the potential difficulty of moving from base-10 measurements to time, while the NSW teaching resource distinguishes decimal calculator values from hours-and-minutes notation.
Ask, “The hour changed from 3 to 4, but did a full hour pass?” In this example it did not: the two jumps total 35 minutes.
Use three short prompts
Ask your child:
- How many minutes are there until 4:00 pm?
- How many minutes are there after 4:00 pm?
- What does 35 minutes describe?
Invite them to explain both jumps. Asking children to explain and justify how they found a duration is consistent with the Year 4 teaching guidance. If the explanation is unclear, revisit one jump together. A single answer should not be treated as proof of mastery or as a diagnosis.
If the first journey feels too demanding, try 3:50 pm → 4:00 pm → 4:10 pm. The jumps are 10 minutes and 10 minutes, so 10 + 10 = 20 minutes.
Try another journey
Suppose you leave for swimming at 8:45 am and arrive at 9:20 am on the same morning. Let your child add the checkpoint and labels before showing the completed version:
8:45 am → 9:00 am → 9:20 am
The two jumps are 15 minutes and 20 minutes, so 15 + 20 = 35 minutes. Ask why the library and swimming journeys can begin at different clock times but have the same duration.
A narrow Year 4 curriculum connection
This activity connects with Year 4 work on duration problems involving am/pm and conversions between units of time, identified as AC9M4M03 in the Mathematics Hub curriculum entry. It is one focused home activity, not coverage of the complete content description.
An optional teacher resource
For teachers seeking a classroom unit, the catalogue description for the Elapsed Time Year 4 Maths Unit states: “The editable presentation introduces number-line jumps, T-charts and Z-charts. The editable quiz provides 10 interleaved question-and-answer pairs. Printable resources include a classroom display, five activity and game resources, six worksheets with answers, a two-page assessment with answers and a five-level rubric.” This optional product is not needed for the paper activity above. Its contents and curriculum mappings have not been independently verified for this article.
Your next step
Choose another familiar journey that starts and finishes on the same day and crosses one hour boundary. Write the start time, the next whole hour and the finish time. Ask your child to label each forward jump in minutes, add the two intervals and explain what the total describes.