Year 5 · Mathematics · Measurement
Time and elapsed time
Read times using am and pm, convert between units of time and work out how long events last by counting on in easy jumps.
Awaiting educator review. This material was drafted by our content team with AI assistance and is waiting for review by a qualified educator. Please check it suits your child before using it. Created 10 October 2026.
These lessons were written around Australian Curriculum strands and matched to New Zealand year levels by age (NZ Year 1 is the first year of school). They are not yet mapped to The New Zealand Curriculum, so check them against your own learning programme.
Learning goals
Learners will
- Use am and pm correctly when reading and writing times.
- Convert between hours, minutes and seconds.
- Calculate elapsed time by counting on in convenient jumps.
Success looks like
- I can say whether a time is in the morning (am) or after midday (pm).
- I know there are 60 seconds in a minute and 60 minutes in an hour.
- I can work out how long an event lasts.
- I can work out a finishing time when I know the start time and how long something takes.
The big idea
A day has 24 hours, but most clocks only show 12. To tell the two halves of the day apart we use am and pm. Times from midnight until just before midday are am, and times from midday until just before midnight are pm. Waking up at 7:00 am is in the morning, while dinner at 6:00 pm is in the evening.
Remember these key facts:
- 60 seconds = 1 minute
- 60 minutes = 1 hour
- 24 hours = 1 day
Elapsed time is how much time passes from the start to the finish of something. The easiest way to find it is to count on from the start time in friendly jumps: first jump to the next whole hour, then jump whole hours, then jump the minutes that are left.
Drawing an empty number line helps. Write the start time at the left and the finish time at the right, then draw your jumps above the line and add them up.
When you know the start time and how long something takes, count forward. If a jump takes you past the hour, remember that the minutes start again from 0 after 59.
Worked examples
Finding how long something lasts
A soccer carnival runs from 9:45 am to 11:10 am. How long does it last?
- Jump from 9:45 am to the next hour, 10:00 am. That is 15 minutes.
- Jump from 10:00 am to 11:00 am. That is 1 hour.
- Jump from 11:00 am to 11:10 am. That is 10 minutes.
- Add the jumps: 1 hour + 15 minutes + 10 minutes = 1 hour 25 minutes.
Answer: The carnival lasts 1 hour 25 minutes.
Finding a finishing time
Lachlan starts reading at 2:50 pm and reads for 25 minutes. What time does he finish?
- Jump from 2:50 pm to 3:00 pm. That uses 10 minutes.
- 25 − 10 = 15 minutes are left.
- Jump 15 minutes from 3:00 pm to 3:15 pm.
Answer: He finishes at 3:15 pm.
Converting units
How many minutes are in 3 hours?
- Each hour has 60 minutes.
- 3 hours is 3 groups of 60 minutes: 3 × 60.
- 3 × 60 = 180.
Answer: There are 180 minutes in 3 hours.
Practice check
Have a go, then check your answers. Each answer comes with an explanation.
Answer guide for parents
Which of these times is in the morning?
7:15 am — am times are between midnight and midday, so 7:15 am is in the morning.
Swimming lessons start at 3:40 pm and last for 35 minutes. What time do they finish?
4:15 pm — 3:40 pm to 4:00 pm is 20 minutes. 35 − 20 = 15 more minutes takes you to 4:15 pm.
How many minutes are in 2 hours?
120 — Each hour has 60 minutes, so 2 hours is 2 × 60 = 120 minutes.
A movie starts at 1:30 pm and finishes at 3:15 pm. How long is the movie?
1 hour 45 minutes — 1:30 pm to 3:00 pm is 1 hour 30 minutes. 3:00 pm to 3:15 pm is 15 more minutes. Total: 1 hour 45 minutes.
How many minutes are there from 10:50 am to 11:20 am?
30 minutes — 10:50 am to 11:00 am is 10 minutes, and 11:00 am to 11:20 am is 20 minutes. 10 + 20 = 30 minutes.
How many seconds are in 1 minute?
60 — There are 60 seconds in every minute.
A train leaves Bendigo at 8:25 am and arrives in Melbourne at 10:25 am. How many hours does the trip take?
2 hours — The minutes are the same (25), and 8 o'clock to 10 o'clock is 2 hours.
A cake needs to bake for 45 minutes. It goes into the oven at 5:30 pm. What time should it come out? (Write your answer like 4:00 pm.)
6:15 pm — 5:30 pm to 6:00 pm is 30 minutes. 45 − 30 = 15 more minutes takes you to 6:15 pm.
Watch out for
- Treating time like a base-10 number, for example thinking 2:50 plus 20 minutes is 2:70. Remind the learner that after 59 minutes the clock goes to the next hour.
- Subtracting times directly, such as 11:10 − 9:45. This gives a wrong answer because there are 60 minutes in an hour, not 100. Counting on in jumps avoids the problem.
- Mixing up 12:00 pm (midday) and 12:00 am (midnight). Link 12 pm to lunchtime and 12 am to the middle of the night.
Tips for parents
- Ask time questions during the day: “We leave at 3:15 pm and the drive takes 20 minutes. When will we arrive?”
- Encourage the learner to draw number lines with jumps. It makes their thinking visible and easy to check.
- Use both analogue and digital clocks so the learner becomes confident with each.
Go further
- Write a timetable for a family day out, with start and finish times for each activity and the length of each one.
- Time some household tasks (brushing teeth, making a bed) and order them from shortest to longest.
- Investigate how many hours you sleep each night for a week and work out the total.