Primary 1 maths · Measurement & time · About 8 minutes
Relate hours and minutes
Keep complete units and extra units separate until their names match.
Start the interactive lesson →Open practice activity
What you will learn
- Relate hours and minutes
Models used: number sentences, stories, tables.
Before you start
An hour is a bundle of 60 minutes
Watch one full trip of the minute hand. Sixty minutes pass while the hour hand moves to the next hour.
Watch one full trip of the minute hand. Sixty minutes pass while the hour hand moves to the next hour.
Clock numbers divide the circle into 12 big steps. Each big step is five minutes: 12 × 5 = 60.
Start at 3 o’clock. The complete bar is the whole. Each labelled section is one part of it.
Two hours contain two bundles of 60 minutes.
2 × 60 = 120 minutes
We count the minutes in each hour and join them. Time uses 60 minutes per hour, not 100.
The complete bar is the whole. Each labelled section is one part of it.
Two hours and 15 minutes contain those 120 minutes, plus 15 more.
120 + 15 = 135 minutes
Only the hour part needs converting. The extra 15 minutes are already in the unit we want.
How could we turn 135 minutes back into hours and minutes?
Take out two complete groups of 60. That uses 120 minutes and leaves 15: 2 hours 15 minutes.
What did the picture help us see?
Two hours and 15 minutes contain those 120 minutes, plus 15 more.
Worked example: A new example, together
Write 77 minutes in hours and minutes.
| Hours | Extra minutes | Total minutes |
|---|---|---|
| ? | ? | 77 |
The same duration in hours and minutes. Read each value with the heading above its column.
Keep complete units and extra units separate until their names match.
Each whole hour contains 60 minutes. Group or ungroup those minutes without changing the duration.
The same duration in hours and minutes Hours Extra minutes Total minutes ? ? 77 The same duration in hours and minutes. Read each value with the heading above its column.
One hour equals 60 minutes.
The same duration in hours and minutes Hours Extra minutes Total minutes ? ? 77 Write 77 minutes in hours and minutes.
1 h 17 min
The same duration in hours and minutes. Read each value with the heading above its column.
One hour equals 60 minutes.
The same duration in hours and minutes Hours Extra minutes Total minutes ? ? 77 The same duration in hours and minutes. Read each value with the heading above its column.
1 × 60 = 60.
The same duration in hours and minutes Hours Extra minutes Total minutes ? ? 77 The same duration in hours and minutes. Read each value with the heading above its column.
60 + 17 = 77 minutes.
The same duration in hours and minutes Hours Extra minutes Total minutes ? ? 77 The same duration in hours and minutes. Read each value with the heading above its column.
Check the result against the question we started with.
77 ÷ 60 gives 1 whole hours with 17 minutes remaining.
We found 1 h 17 min. Each whole hour contains 60 minutes. Group or ungroup those minutes without changing the duration.
The same duration in hours and minutes Hours Extra minutes Total minutes ? ? 77
Common mistakes to discuss
- The hundred-minute hour. An hour holds 60 minutes. 77 minutes is 1 h 17 min, not 1 h 77 min or 1.77 hours.
Check your understanding
- Relate hours and minutes
- rename a duration without changing how long it lasts
- check the answer against the original quantities and units
Explain your reasoning to an adult, then try a fresh question in the interactive lesson. A result from one attempt is not proof of lasting mastery.
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