Minutes and elapsed time

Count the small gaps

There are 60 minute gaps around a clock. Each printed number is five minutes after the previous one.

If the long hand is three small gaps after 8, it shows 40 + 3 = 43 minutes. If the short hand is between 7 and 8, the time is 7:43. The hour is still seven because the short hand has not reached eight.

The hands do not distinguish morning from afternoon. Check the day context before choosing am or pm. If those labels are unfamiliar, revisit am and pm.

Measure how long an activity takes

Choose a clock that shows hours and minutes. Read and write down the time when an activity starts, including am or pm. Use the same clock to record when it finishes. Those two observations let you find the duration.

For example, an activity starts at 10:20 am and finishes at 11:05 am on the same day. There are 40 min to eleven o’clock and 5 min after it. The duration is 45 min, or 0 h 45 min. The finish time, 11:05 am, is not the duration.

Try measuring a short activity, such as tidying a shelf. Record its start and finish on paper, then find the hours and minutes between them. Check both readings before calculating. A written calculation can check your use of recorded times; it cannot check whether you read the real clock at the right moments.

An hour is 60 minutes

To change 2 h 15 min to minutes, first count 2 × 60 = 120 minutes in the two hours. Then add 15: 135 min.

To change 95 min to hours and minutes, make one group of 60 min. There are 35 min left, so 95 min = 1 h 35 min.

An hour does not contain 100 minutes. Writing 1 h 35 min as 135 min would add a hundred minutes for the hour instead of sixty.

Check your understanding 1 Convert the units

How many minutes are in 1 h 20 min?

Total minutes

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80 min: 60 + 20 = 80.

Use a jump to the next hour

A game begins at 9:48 am and ends at 10:12 am. From 9:48 to 10:00 is 12 min. From 10:00 to 10:12 is another 12 min. The game lasts 24 min.

The clock labels are times. The answer “24 min” is a duration: how long the game lasts.

Check your understanding 2 Find an ending time

A bus leaves at 2:47 pm. The journey takes 28 min. When does it arrive? Show how you crossed the hour.

Your answer or drawing on paper

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There are 13 min to 3:00 pm. Of the 28 min, 15 min remain, so the bus arrives at 3:15 pm. Check 13 + 15 = 28.

Check your understanding 3 Keep both parts

Convert 125 min to hours and minutes. Then convert your answer back to minutes.

Hours

Minutes left after complete hours

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125 min is 2 h 5 min. Two hours are 120 min, leaving 5 min. Converting back gives 120 + 5 = 125 min.

For 120 min, write 2 h 0 min. For 35 min, write 0 h 35 min. Zero keeps an empty part clear. The minutes left after taking out complete hours must be less than 60.