Year 3 · Chapter 7

Time

By the end of this chapter you will be able to

Read the time to the nearest minute on a clock face with numbers and with Roman numerals
Write the time on a 12-hour clock and on a 24-hour clock, and change between the two
Change between seconds, minutes and hours, and record times in these units
Know how many days are in each month, and find a leap year
Work out how long an event lasts, from a start time and an end time
Compare the durations of events, using timetables

You should already know

Telling the time to the hour and half past, and drawing the hands on a clock (Year 2, Chapter 7)
Adding and subtracting numbers with up to 3 digits (Year 3, Chapter 2)
Multiplication facts for the 3, 4 and 8 times tables, used to change minutes to seconds (Year 3, Chapter 3)

Where this leads

Converting between units of time with decimals, and calculating with timetables (Year 4)
Finding durations across midnight and comparing time in more complex problems (Year 4 and later)

National Curriculum for England, Key Stage 2 mathematics, Year 3. Content: Tell and write the time from an analogue clock, including Roman numerals I to XII, and 12-hour and 24-hour clocks, Estimate and read time with increasing accuracy to the nearest minute, Record and compare time in terms of seconds, minutes and hours; use o’clock, a.m., p.m., morning, afternoon, noon and midnight, Know the number of seconds in a minute and the number of days in each month, year and leap year, Compare durations of events.

Exercise P Do you remember?

Non-calculator

FHow many minutes are there in one hour?

Done

FWhat time does this clock show?

Done

FWrite the time shown on this clock.

Done

FHow many days are there in one week?

Done

FA film starts at 2 o’clock and lasts 1 hour. What time does it finish?

Done

7.1

Reading a clock to the minute

Year 3
Estimate and read time with increasing accuracy to the nearest minute

Video lesson: Reading a clock to the minuteComing soon

Sam is waiting for the school bus. He looks up at the clock on the wall, and he tells his friend the time.

An analogue clock has two hands. The short hand shows the hour. The long hand shows the minutes.

There are 60 small marks around the edge, one for each minute. The bigger marks are every 5 minutes. Each number on the clock is 5 minutes, so the long hand on 1 means 5 minutes past, the long hand on 2 means 10 minutes past, and so on.

To read the time, first look at the short hand to find the hour. Then count the minutes on the long hand: count in fives from 12, then count on one minute at a time.

You can start with an estimate, and then read the exact time. This helps you check your answer.

The short hand is between 9 and 10, and the long hand is on 9. The time is 9:45.

Key ideas

The short hand shows the hour.
The long hand shows the minutes.
Each number on the clock is 5 minutes.
Count in fives, then count on the single minutes.
Write the time with a colon, such as 4:07, with two digits for the minutes.

Worked example 7.1.1

What time is shown on this clock?

Key words. The short hand shows the hour. The long hand shows the minutes. There are 60 minutes in one hour.

Method. Read the short hand for the hour. Then count the minutes on the long hand, in fives.

Look at the short hand. The short hand has passed the number 4. It shows the hour, which is 4.
Hour = 4
Look at the long hand. The long hand shows the minutes. Count in fives from 12, then count the single minutes.
5, 10, 15, then 2 more = 17
Write the time. Write the hour, a colon, then the minutes with two digits.
4:17

Check. 4:00 plus 17 minutes is 4:17. ✓

Watch out. Use the number the short hand has just passed, even if the time is nearly the next hour. Do not read the long hand as the hour.

Worked example 7.1.2

Estimate first: the long hand is just past the 8, so the time is about 40 minutes past 10. Now read the exact time.

Key words. The short hand shows the hour. The long hand shows the minutes. There are 60 minutes in one hour.

Method. Read the short hand for the hour. Then count the minutes on the long hand, in fives.

Look at the short hand. The short hand has passed the number 10. It shows the hour, which is 10.
Hour = 10
Look at the long hand. The long hand shows the minutes. Count in fives from 12, then count the single minutes.
5, 10, 15, 20, 25, 30, 35, 40, then 2 more = 42
Write the time. Write the hour, a colon, then the minutes with two digits.
10:42

Check. 10:00 plus 42 minutes is 10:42. ✓

Watch out. Use the number the short hand has just passed, even if the time is nearly the next hour. Do not read the long hand as the hour.

Worked example 7.1.3

Sam says the time is about 8 o’clock. Write the exact time shown on this clock.

Key words. The short hand shows the hour. The long hand shows the minutes. There are 60 minutes in one hour.

Method. Read the short hand for the hour. Then count the minutes on the long hand, in fives.

Look at the short hand. The short hand has passed the number 7. It shows the hour, which is 7.
Hour = 7
Look at the long hand. The long hand shows the minutes. Count in fives from 12, then count the single minutes.
5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, then 3 more = 58
Write the time. Write the hour, a colon, then the minutes with two digits.
7:58

Check. 7:00 plus 58 minutes is 7:58. ✓

Watch out. Use the number the short hand has just passed, even if the time is nearly the next hour. Do not read the long hand as the hour.

Watch out

Watch out: the long hand is not the hour. A long hand on 3 does not mean 3 o’clock. Read the short hand for the hour, and the long hand for the minutes.

Exam tip

Grown-up tip. Use a real clock with moveable hands, or a paper clock. Ask your child to show 7:58 on it, then ask: "Which hand tells us the hour? How many minutes is the long hand past?"

7.2

Roman numerals on a clock face

Year 3
Tell and write the time from an analogue clock, including Roman numerals I to XII

Video lesson: Roman numerals on a clock faceComing soon

Ruby visits her grandad. In his hall there is an old clock with Roman numerals on its face, instead of the numbers we use every day.

Roman numerals are letters that stand for numbers. The numerals I to XII go round a clock in the same order as the numbers 1 to 12.

1	2	3	4	5	6
I	II	III	IV	V	VI
7	8	9	10	11	12
VII	VIII	IX	X	XI	XII

The short hand still shows the hour, and the long hand still shows the minutes. Each numeral on the long hand is a number of fives: V is 5 minutes, X is 10 minutes, and so on.

Two patterns are important. IV is 4, because we take 1 away from 5. IX is 9, because we take 1 away from 10. The small letter in front means “take away”.

This clock shows 3:15. The long hand is on III, which is 15 minutes.

Key ideas

I is 1, V is 5 and X is 10.
The numerals I to XII go round the clock in order.
IV is 4 and IX is 9, because the small letter comes first.
The short hand shows the hour, and the long hand shows the minutes, exactly as on any other clock.

Worked example 7.2.1

Read the time shown on this clock with Roman numerals.

Key words. The short hand shows the hour. The long hand shows the minutes. There are 60 minutes in one hour.

Method. Read the short hand for the hour. Then count the minutes on the long hand, in fives.

Look at the short hand. The short hand has passed the number IX (9). It shows the hour, which is 9.
Hour = 9
Look at the long hand. The long hand shows the minutes. Count in fives from 12, then count the single minutes.
5, 10, 15, 20 = 20
Write the time. Write the hour, a colon, then the minutes with two digits.
9:20

Check. 9:00 plus 20 minutes is 9:20. ✓

Watch out. Use the number the short hand has just passed, even if the time is nearly the next hour. Do not read the long hand as the hour.

Worked example 7.2.2

Write the Roman numeral XI as a number.

Key words. Roman numerals are letters that stand for numbers. I is 1, V is 5 and X is 10.

Method. Add the values of the letters. If a small letter is in front of a bigger one, take it away.

Read the letters from left to right. Each letter has a value: I is 1, V is 5 and X is 10.
XI
Add the values. Take away when a small letter comes first. Where a small letter is in front of a bigger one, take the small one away. Otherwise, add.
10 + 1 = 11
Write the answer. The answer is an ordinary number.
11

Check. 11 in Roman numerals is XI. ✓

Watch out. Do not add IV as 1 + 5. IV is 4, not 6.

Worked example 7.2.3

Write the number 9 using Roman numerals.

Key words. Roman numerals are letters that stand for numbers. I is 1, V is 5 and X is 10.

Method. Use the biggest letters first. Use IV for 4 and IX for 9.

Use the values of the letters. X is 10, V is 5 and I is 1. For 4 and 9 the small letter goes in front: IV and IX.
X = 10, V = 5, I = 1
Build the number from the biggest letters first. Check the letters add up to the number.
10 − 1 = 9
Write the answer. Put the letters together, in the right order.
IX

Check. 10 − 1 = 9. ✓

Watch out. Do not write IIII for 4 or VIIII for 9. Use IV and IX.

Watch out

Watch out: IV is not 6, and IX is not 11. The small letter in front is taken away. I + V = 6 is not IV, and X + I = 11 is not IX.

Exam tip

Grown-up tip. Write the numerals I to XII on sticky notes and stick them on paper circles. Ask your child to put the numerals in order, then point to IV and IX and say how many each one means.

7.3

12-hour and 24-hour clocks

Year 3
Tell and write the time using 12-hour and 24-hour clocks; morning, afternoon, noon and midnight

Video lesson: 12-hour and 24-hour clocksComing soon

Ella’s train leaves at 17:45. The station timetable uses a 24-hour clock. Her dad says the train leaves at quarter to six in the evening.

Most clocks at home use a 12-hour clock. It counts 12 hours, then starts again. We write a.m. for the time from midnight to noon, and p.m. for the time from noon to midnight.

Timetables often use a 24-hour clock. It counts the hours from 00 to 23. The times after noon are 13:00 to 23:59. A 24-hour time always has four digits.

To change a p.m. time to a 24-hour time, add 12 to the hour. For example, 3:15 p.m. is 15:15. The exception is 12 p.m., which is noon, and is already 12. Midnight is 00:00 on a 24-hour clock.

12-hour clock	24-hour clock	Part of the day
12:00 a.m.	00:00	midnight
7:30 a.m.	07:30	morning
12:00 p.m.	12:00	noon
3:15 p.m.	15:15	afternoon
8:30 p.m.	20:30	evening

Key ideas

a.m. is from midnight to noon. p.m. is from noon to midnight.
A 24-hour clock counts from 00 to 23 and uses four digits.
For a p.m. time, add 12 to the hour, except for 12 p.m.
Midnight is 00:00 and noon is 12:00 on a 24-hour clock.

Worked example 7.3.1

Write 3:15 p.m. on a 24-hour clock.

Key words. A 24-hour clock counts the hours from 00 to 23. A 24-hour time always has four digits, such as 07:30 or 15:15.

Method. Use a.m. and p.m. to decide the hour. For p.m. times, add 12 to the hour, except 12 p.m. (noon).

Look at a.m. or p.m. a.m. is before noon. p.m. is after noon.
3:15 p.m.
Add 12 hours. 3 p.m. is 3 hours after noon, so add 12 to the hour.
3 + 12 = 15
Write the answer with four digits. A 24-hour time always has two digits for the hour and two for the minutes.
15:15

Check. 15:15 and 3:15 p.m. are the same time. ✓

Watch out. Do not keep the hour the same for a p.m. time. Add 12 to the hour.

Worked example 7.3.2

Write the time 06:45 on a 12-hour clock. Use a.m. or p.m.

Key words. a.m. is the time from midnight to noon. p.m. is the time from noon to midnight. Noon is 12 p.m. and midnight is 12 a.m.

Method. Hours 00 to 11 are a.m. For hours after noon, take 12 away from the hour and write p.m.

Look at the hour. Hours 00 to 11 are a.m. Hours 12 to 23 are p.m.
06:45
Keep the hour the same. The hour is before noon, so the time is a.m.
6 = 6 a.m.
Write the answer. Write the hour, the minutes, then a.m. or p.m.
6:45 a.m.

Check. 6:45 a.m. is the same time as 06:45 on a 24-hour clock. ✓

Watch out. Do not add 12 to a morning time. Times before noon are a.m.

Worked example 7.3.3

Write 12:00 p.m., which is noon, on a 24-hour clock.

Key words. A 24-hour clock counts the hours from 00 to 23. A 24-hour time always has four digits, such as 07:30 or 15:15.

Method. Use a.m. and p.m. to decide the hour. For p.m. times, add 12 to the hour, except 12 p.m. (noon).

Look at a.m. or p.m. a.m. is before noon. p.m. is after noon.
12:00 p.m.
Keep the hour as 12. 12 p.m. is noon, which is already 12 on a 24-hour clock.
12 p.m. = 12
Write the answer with four digits. A 24-hour time always has two digits for the hour and two for the minutes.
12:00

Check. 12:00 and 12:00 p.m. are the same time. ✓

Watch out. Noon is 12:00 on a 24-hour clock, not 00:00. Only midnight is 00:00.

Watch out

Watch out: 3:15 p.m. is 15:15, not 03:15. A p.m. time needs 12 added to the hour. Also, 12:30 a.m. is just after midnight, not after noon.

Exam tip

Grown-up tip. Look at a real bus or train timetable together. Ask your child to say the time in both forms, for example "Half past seven in the evening is 19:30".

7.4

Seconds, minutes and hours

Year 3
Record and compare time in terms of seconds, minutes and hours; know the number of seconds in a minute

Video lesson: Seconds, minutes and hoursComing soon

Jaden times how long it takes to tie his shoelaces. He uses a stopwatch, and he writes each time in seconds so that his times are easy to compare.

Time can be measured in seconds, minutes and hours. Each unit is made of smaller units:

Unit	Equals
1 minute	60 seconds
1 hour	60 minutes
1 day	24 hours
1 week	7 days

To change a bigger unit to a smaller unit, multiply. For example, 4 minutes is 4 × 60 seconds, which is 240 seconds.

To change seconds to minutes and seconds, divide by 60. The answer is the minutes, and the number left over is the seconds. For example, 150 seconds is 2 minutes and 30 seconds, which we write as 2:30.

Key ideas

There are 60 seconds in 1 minute.
There are 60 minutes in 1 hour, and 24 hours in 1 day.
To change a bigger unit to a smaller one, multiply.
To change seconds to minutes and seconds, divide by 60.

Worked example 7.4.1

How many seconds are there in 4 minutes?

Key words. There are 60 seconds in a minute, 60 minutes in an hour and 24 hours in a day.

Method. Multiply the number of minutes by 60 to find the number of seconds.

Write the rule. This tells us how many small units make one big unit.
1 minute = 60 seconds
Multiply. There are 4 minutes, so multiply by 60.
4 × 60 = 240
Write the answer. The answer is in seconds.
240

Check. 240 ÷ 60 = 4. ✓

Watch out. A smaller unit gives more of them, so the number gets bigger. Multiply, do not divide.

Worked example 7.4.2

Jaden’s stopwatch shows 2 minutes 15 seconds. How many seconds is that?

Key words. There are 60 seconds in a minute, 60 minutes in an hour and 24 hours in a day.

Method. Change the minutes to seconds, then add the seconds.

Change the minutes to seconds. There are 60 seconds in each minute.
2 × 60 = 120 seconds
Add the seconds that are left. Add the seconds to the total.
120 + 15 = 135
Write the answer. The answer is in seconds.
135

Check. 2 × 60 + 15 = 135. ✓

Watch out. Change the minutes to seconds before you add the seconds. Do not add the minutes and the seconds directly.

Worked example 7.4.3

Write 150 seconds as minutes and seconds, using a colon.

Key words. There are 60 seconds in a minute, 60 minutes in an hour and 24 hours in a day.

Method. Divide the seconds by 60. The answer is the minutes, and the remainder is the seconds.

Count the whole minutes in the seconds. Each minute is 60 seconds, so divide by 60.
150 ÷ 60 = 2 remainder 30
Write the seconds that are left over. The remainder is the number of seconds.
30 seconds
Write the answer as minutes and seconds. Write the minutes, a colon, then the seconds with two digits.
2:30

Check. 2 × 60 + 30 = 150. ✓

Watch out. Write the seconds with two digits, so 5 seconds is 05.

Watch out

Watch out: 2 minutes 15 seconds is not 215 seconds. Change the minutes to seconds first: 2 × 60 = 120, then add 15 to get 135.

Exam tip

Grown-up tip. Use a kitchen timer or a phone stopwatch. Time how long your child takes to do a task, then ask them to write the time in seconds and then in minutes and seconds.

7.5

Days in months, years and leap years

Year 3
Know the number of days in each month, year and leap year

Video lesson: Days in months, years and leap yearsComing soon

Ruby is planning a birthday party for next March. She uses a calendar to count the days between now and the party, and she needs to know how many days each month has.

A year has 12 months. Each month has 28, 29, 30 or 31 days.

Number of days	Months
31	January, March, May, July, August, October, December
30	April, June, September, November
28, or 29 in a leap year	February

A year has 365 days. A leap year has 366 days, because February has 29 days instead of 28.

A year is a leap year when it can be divided by 4 with no remainder. For example, 2028 is a leap year, because 2028 ÷ 4 = 507 with no remainder. 2026 is not a leap year, because 2026 ÷ 4 leaves a remainder of 2. (Years that end in 00 follow an extra rule, which you will learn later. This chapter does not use them.)

Key ideas

31 days: January, March, May, July, August, October, December.
30 days: April, June, September, November.
February has 28 days, or 29 days in a leap year.
A leap year divides by 4 with no remainder, and has 366 days.

Worked example 7.5.1

How many days are there in June?

Key words. A leap year has 366 days, with 29 days in February. A year that is not a leap year has 365 days.

Method. Learn the three groups of months. Then find which group the month is in.

Find the month in its group. Months with 31 days: January, March, May, July, August, October and December. Months with 30 days: April, June, September and November. February has 28 days, or 29 in a leap year.
June
Read the number of days. Use the number for the group that the month is in.
June has 30 days
Write the answer. Write only the number of days.
30

Check. Seven months have 31 days, four have 30 and February has 28: 7 × 31 + 4 × 30 + 28 = 365. ✓

Watch out. Do not guess. Use the groups of months, and remember February is the short month.

Worked example 7.5.2

Is 2028 a leap year? Write Yes or No.

Key words. A leap year has 366 days, with 29 days in February. A year that is not a leap year has 365 days.

Method. Divide the year by 4. If there is no remainder, it is a leap year.

Divide the year by 4. A leap year has no remainder when it is divided by 4.
2028 ÷ 4 = 507 remainder 0
Decide. No remainder means a leap year, so February has 29 days. A remainder means it is not a leap year.
Remainder 0, so it is a leap year
Write the answer. Write Yes or No.
Yes

Check. 2028 = 507 × 4 + 0. ✓

Watch out. Check the remainder, not the last digit. 2028 is a leap year, and 2026 is not.

Worked example 7.5.3

How many days are there in February and March 2027 altogether?

Key words. A leap year has 366 days, with 29 days in February. A year that is not a leap year has 365 days.

Method. Find the number of days in each month, then add them together.

Find the number of days in each month. Use the groups of months.
February 2027 = 28; March = 31
Add the days together. Add the number of days from each month.
28 + 31 = 59
Write the answer. The answer is the total number of days.
59

Check. In reverse order: 31 + 28 = 59. ✓

Watch out. Use 29 days for February only in a leap year. Otherwise it has 28 days.

Watch out

Watch out: not every month has 30 days. February is the short month, and March has 31 days. A leap year has an extra day in February, so it has 366 days.

Exam tip

Grown-up tip. Use a calendar. Ask your child to count the months with 31 days on their knuckles: January is on the first knuckle, February is in the gap, March is on the next knuckle, and so on.

7.6

Durations, timetables and comparing times

Year 3
Compare durations of events; use timetables; find the time taken between two times

Video lesson: Durations, timetables and comparing timesComing soon

Mr Patel shows his class the timetable for Monday. The children work out how long each lesson lasts, so that they know how much time they have.

Lesson	Starts	Ends
Register and assembly	9:00 a.m.	9:20 a.m.
Maths	9:20 a.m.	10:05 a.m.
Break	10:05 a.m.	10:25 a.m.
English	10:25 a.m.	11:40 a.m.
Lunch	12:00 p.m.	1:00 p.m.
Science	1:00 p.m.	2:10 p.m.
Art	2:10 p.m.	3:00 p.m.

The duration is the time from the start of an event to the end. To find it, count on from the start time to the end time. First count on to the next hour, then count on in whole hours, then count on the minutes that are left.

For example, from 9:20 a.m. to 10:05 a.m. we count 40 minutes to 10:00, and then 5 minutes more. The lesson lasts 45 minutes.

To compare two durations, write both in minutes. The longer duration has the bigger number of minutes. The difference is how much longer.

Key ideas

The duration is the time from the start to the end.
Count on to the next hour, then in whole hours, then the minutes.
Write both durations in the same unit before you compare them.
Write hours and minutes with a colon, such as 1:25 for 1 hour 25 minutes.

Worked example 7.6.1

The Maths lesson starts at 9:20 a.m. and ends at 10:05 a.m. How many minutes is the lesson?

Key words. A duration is how long something lasts. We find it by counting on from the start time to the end time.

Method. Count on from the start time to the end time in jumps. Add the jumps to find the duration.

Write the start time and the end time. The duration is the time from the start to the end.
9:20 a.m. to 10:05 a.m.
Count on to 10:00 a.m. We add 40 minutes to get there.
9:20 a.m. + 40 min = 10:00 a.m.
Count on to 10:05 a.m. We add 5 minutes to get there.
10:00 a.m. + 5 min = 10:05 a.m.
Add up the jumps. The duration is all the jumps added together.
40 + 5 = 45 minutes
Write the answer. The answer is in minutes.
45

Check. 9:20 a.m. plus 45 minutes is 10:05 a.m. ✓

Watch out. Work out the minutes as well as the hours. Do not subtract the hour numbers and the minute numbers separately.

Worked example 7.6.2

Ali’s football practice starts at 1:35 p.m. and ends at 3:10 p.m. How many minutes is the practice?

Key words. A duration is how long something lasts. We find it by counting on from the start time to the end time.

Method. Count on from the start time to the end time in jumps. Add the jumps to find the duration.

Write the start time and the end time. The duration is the time from the start to the end.
1:35 p.m. to 3:10 p.m.
Count on to 2:00 p.m. We add 25 minutes to get there.
1:35 p.m. + 25 min = 2:00 p.m.
Count on to 3:00 p.m. We add 60 minutes to get there.
2:00 p.m. + 60 min = 3:00 p.m.
Count on to 3:10 p.m. We add 10 minutes to get there.
3:00 p.m. + 10 min = 3:10 p.m.
Add up the jumps. The duration is all the jumps added together.
25 + 60 + 10 = 95 minutes
Write the answer. The answer is in minutes.
95

Check. 1:35 p.m. plus 95 minutes is 3:10 p.m. ✓

Watch out. Work out the minutes as well as the hours. Do not subtract the hour numbers and the minute numbers separately.

Worked example 7.6.3

Ben’s lunch club runs from 11:50 a.m. until 12:20 p.m. How many minutes does it last?

Key words. A duration is how long something lasts. We find it by counting on from the start time to the end time.

Method. Count on from the start time to the end time in jumps. Add the jumps to find the duration.

Write the start time and the end time. The duration is the time from the start to the end.
11:50 a.m. to 12:20 p.m.
Count on to 12:00 p.m. We add 10 minutes to get there.
11:50 a.m. + 10 min = 12:00 p.m.
Count on to 12:20 p.m. We add 20 minutes to get there.
12:00 p.m. + 20 min = 12:20 p.m.
Add up the jumps. The duration is all the jumps added together.
10 + 20 = 30 minutes
Write the answer. The answer is in minutes.
30

Check. 11:50 a.m. plus 30 minutes is 12:20 p.m. ✓

Watch out. Work out the minutes as well as the hours. Do not subtract the hour numbers and the minute numbers separately.

Watch out

Watch out: the times cross noon. 11:50 a.m. to 12:20 p.m. is 30 minutes, not 70 minutes. Do not subtract the hour numbers and the minute numbers separately.

Exam tip

Grown-up tip. Take a clock and set it to the start time. Ask your child to move the long hand forward to the end time, counting the minutes as they go. Then ask: "How many minutes did the hand move?"

Exercise 7F Durations and timetables

Non-calculator

FHow many minutes is the Maths lesson?

Lesson	Starts	Ends
Register and assembly	9:00 a.m.	9:20 a.m.
Maths	9:20 a.m.	10:05 a.m.
Break	10:05 a.m.	10:25 a.m.
English	10:25 a.m.	11:40 a.m.
Lunch	12:00 p.m.	1:00 p.m.
Science	1:00 p.m.	2:10 p.m.
Art	2:10 p.m.	3:00 p.m.

Done

FHow many minutes is lunch?

Lesson	Starts	Ends
Register and assembly	9:00 a.m.	9:20 a.m.
Maths	9:20 a.m.	10:05 a.m.
Break	10:05 a.m.	10:25 a.m.
English	10:25 a.m.	11:40 a.m.
Lunch	12:00 p.m.	1:00 p.m.
Science	1:00 p.m.	2:10 p.m.
Art	2:10 p.m.	3:00 p.m.

Done

FHow long is the English lesson? Write the answer in minutes.

Lesson	Starts	Ends
Register and assembly	9:00 a.m.	9:20 a.m.
Maths	9:20 a.m.	10:05 a.m.
Break	10:05 a.m.	10:25 a.m.
English	10:25 a.m.	11:40 a.m.
Lunch	12:00 p.m.	1:00 p.m.
Science	1:00 p.m.	2:10 p.m.
Art	2:10 p.m.	3:00 p.m.

Done

FHow long is the Science lesson? Write the answer as hours and minutes, like 1:10 for 1 hour 10 minutes.

Lesson	Starts	Ends
Register and assembly	9:00 a.m.	9:20 a.m.
Maths	9:20 a.m.	10:05 a.m.
Break	10:05 a.m.	10:25 a.m.
English	10:25 a.m.	11:40 a.m.
Lunch	12:00 p.m.	1:00 p.m.
Science	1:00 p.m.	2:10 p.m.
Art	2:10 p.m.	3:00 p.m.

Done

FHow long is the Art lesson? Write the answer in minutes.

Lesson	Starts	Ends
Register and assembly	9:00 a.m.	9:20 a.m.
Maths	9:20 a.m.	10:05 a.m.
Break	10:05 a.m.	10:25 a.m.
English	10:25 a.m.	11:40 a.m.
Lunch	12:00 p.m.	1:00 p.m.
Science	1:00 p.m.	2:10 p.m.
Art	2:10 p.m.	3:00 p.m.

Done

FAli starts reading at 4:15 p.m. and stops at 4:50 p.m. How many minutes does he read for?

Done

PSA train leaves at 7:40 a.m. and arrives at 9:05 a.m. How long is the journey? Write hours and minutes, like 1:25.

Done

PSUse the timetable to answer both parts.

Lesson	Starts	Ends
Register and assembly	9:00 a.m.	9:20 a.m.
Maths	9:20 a.m.	10:05 a.m.
Break	10:05 a.m.	10:25 a.m.
English	10:25 a.m.	11:40 a.m.
Lunch	12:00 p.m.	1:00 p.m.
Science	1:00 p.m.	2:10 p.m.
Art	2:10 p.m.	3:00 p.m.

(a)How many minutes are the Maths and English lessons altogether?

(b)How many minutes longer is the English lesson than the Maths lesson?

Done

PSAli’s film lasts 1 hour 35 minutes. Ben’s film lasts 1 hour 50 minutes. How many minutes longer is Ben’s film?

Done

PSLesson A runs from 10:15 a.m. to 11:00 a.m. Lesson B runs from 1:00 p.m. to 1:40 p.m. How many minutes longer is the longer lesson?

Done

PSArt starts at 2:10 p.m. Ali arrives 15 minutes late. What time does he arrive? Write it on a 24-hour clock.

Done

RSara says that lunch and the Maths lesson last the same length of time, because both are about an hour. Is she right? Explain.

Done

Chapter summary

Skill	Method
Reading an analogue clock	The short hand gives the hour. The long hand gives the minutes: count in fives from 12, then count on the single minutes.
Roman numerals	I is 1, V is 5 and X is 10. A small letter in front is taken away: IV is 4, IX is 9.
12-hour and 24-hour clocks	Add 12 to the hour for p.m. times, except 12 p.m. Hours 00 to 11 are a.m. Midnight is 00:00.
Seconds, minutes and hours	There are 60 seconds in a minute, 60 minutes in an hour and 24 hours in a day. Multiply to change to a smaller unit.
Days in months and years	Months have 28, 29, 30 or 31 days. A year has 365 days, or 366 in a leap year. A leap year divides by 4 with no remainder.
Durations and timetables	Count on from the start time to the end time: to the next hour, then in whole hours, then the minutes left over.

Can you…?

I can read the time to the minute on an analogue clock with Arabic numerals.
I can read and write the time on a clock with Roman numerals I to XII.
I can change between 12-hour times with a.m. and p.m., and 24-hour times.
I know the number of seconds in a minute, minutes in an hour and hours in a day.
I can change between seconds, minutes and hours, and compare them.
I know the number of days in each month, and how to find a leap year.
I can find the duration between two times, and compare two durations.

Key terms

Analogue clock: A clock with a face and hands, which shows the time with the hands.
Hour hand: The short hand, which shows the hour.
Minute hand: The long hand, which shows the minutes.
Roman numerals: Letters that stand for numbers, such as I for 1, V for 5 and X for 10.
12-hour clock: A clock that counts 12 hours, with a.m. before noon and p.m. after noon.
24-hour clock: A clock that counts the hours from 00 to 23, with four digits, such as 15:15.
Noon and midnight: Noon is 12 p.m. in the day. Midnight is 12 a.m. at the start of the day, which is 00:00.
Duration: How long something lasts, from the start time to the end time.
Leap year: A year with 366 days, with 29 days in February. It can be divided by 4 with no remainder. Years that end in 00 follow an extra rule, which is not needed in this chapter.
Timetable: A list that shows when each event or lesson starts and ends.

Total 19 marks. Allow about 19 minutes.

Exercise 7X Practice test questions

Non-calculator

FWrite the time shown on this clock with Roman numerals.[1 mark]

Done

FWrite 6:15 p.m. as a 24-hour time.[1 mark]

Done

FHow many seconds are there in 7 minutes?[1 mark]

Done

FHow many days are there in April, May and June altogether?[2 marks]

Done

FIs 2036 a leap year? Write Yes or No.[2 marks]

Done

FElla’s swimming lesson starts at 4:40 p.m. and ends at 5:25 p.m. How many minutes is the lesson?[2 marks]

Done

FWrite 2 hours 45 minutes in minutes.[2 marks]

Done

FWrite 16:05 as a 12-hour time, using a.m. or p.m.[2 marks]

Done

FRavi’s bus leaves at 1:20 p.m. The journey takes 75 minutes.[3 marks]

(a)What time does the bus arrive? Use a.m. or p.m.

(b)Write the arrival time on a 24-hour clock.

Done

FUse the sports day timetable to answer the three parts.[3 marks]

Lesson	Starts	Ends
Sack race	1:00 p.m.	1:20 p.m.
Relay	1:20 p.m.	2:05 p.m.
Tug of war	2:05 p.m.	2:35 p.m.

(a)How many minutes does the relay last?

(b)How many minutes longer is the relay than the sack race?

(c)The tug of war starts at 2:05 p.m. and lasts 30 minutes. What time does it end? Write it on a 24-hour clock.

Done

← Chapter 6: Money Chapter 8: Shapes and angles →

Time

By the end of this chapter you will be able to

You should already know

Where this leads

Exercise P Do you remember?

Reading a clock to the minute

Key ideas

Watch out

Exam tip

Exercise 7A Reading the time on a clock face

Roman numerals on a clock face

Key ideas

Watch out

Exam tip

Exercise 7B Roman numerals on the clock

12-hour and 24-hour clocks

Key ideas

Watch out

Exam tip

Exercise 7C Changing between 12-hour and 24-hour times

Seconds, minutes and hours

Key ideas

Watch out

Exam tip

Exercise 7D Changing and comparing times

Days in months, years and leap years

Key ideas

Watch out

Exam tip

Exercise 7E Days in months and years

Durations, timetables and comparing times

Key ideas

Watch out

Exam tip

Exercise 7F Durations and timetables

Chapter summary

Can you…?

Key terms

Exercise 7Z Check-up

Exercise 7X Practice test questions