Year 1 maths · Key Stage 1 · Measurement

Year 1 measures: length, weight, capacity, time and money

Year 1 measurement is about getting a feel for size, amount and time. Children compare and describe lengths, weights, capacities and times, and begin to measure them. They recognise coins and notes, put events in order, learn the days of the week and the months of the year, and tell the time to the hour and half past the hour. Everything is practical and uses real objects and everyday words.

Length, mass, capacity, time and money, explained

Measurement in Year 1 starts with comparing, before any numbers are involved. Children use words such as long and short, taller and shorter, heavier and lighter, full, empty, half full and quarter full, quicker and slower, and earlier and later. They solve practical problems: which of these ribbons is the longest, which bag is the lightest, which jug holds the most. They also meet double and half in the context of length, such as a string that is double the length of another. In Year 1, mass and weight are used to mean the same thing, as are capacity and volume, so you will hear both words used for how heavy something is and both for how much a container holds.

Next, children measure and begin to record. They start with non-standard units that they can easily make or find: cubes, hand spans, scoops and spoonfuls, and claps or jumps for time. Then they move on to common standard units, using a ruler, balance scales and a measuring jug. A fair measure has some rules that are worth practising: start at the same edge or at zero, leave no gaps and no overlaps, and use units that are all the same size. Time is measured in hours, minutes and seconds, for example by seeing how many star jumps can be done in one minute.

Children also recognise coins and notes and know their value: 1p, 2p, 5p, 10p, 20p, 50p, £1 and £2 coins, and £5, £10, £20 and £50 notes. The aim in Year 1 is to know what each one is worth. Combining coins to make an amount and giving change come in Year 2. The coins are not in size order of value, which makes real handling much more useful than pictures.

Time includes several linked ideas. Children put events in order using before and after, first, next, today, yesterday, tomorrow, morning, afternoon and evening, often by sequencing the events of a day or a story. They learn the days of the week, weeks, months and years, usually with a class calendar. They also learn to tell the time to the hour (“three o’clock”) and the half hour (“half past three”), and to draw the hands on a clock face to show these times. Reading the time to the nearest five minutes and saying quarter past and quarter to are Year 2 skills.

Words your child will hear

Mass (weight): How heavy something is. In Year 1 both words are used, and children compare using heavier and lighter.
Capacity: How much a container can hold. A bucket has a bigger capacity than a cup.
Non-standard unit: A measuring unit that is not an official one, such as a cube, hand span or scoop.
Standard unit: A unit everyone agrees on, such as a centimetre on a ruler, so measurements can be compared.
Sequence: Put events in the order in which they happen: first, next, then, last.
O’clock and half past: The two times Year 1 children read: exactly on the hour, and thirty minutes after it.
Hour hand and minute hand: The short hand shows the hour. The long hand shows the minutes past the hour.

What the National Curriculum says

In Year 1, pupils should be taught to:

Compare, describe and solve practical problems for: lengths and heights [for example, long/short, longer/shorter, tall/short, double/half]; mass/weight [for example, heavy/light, heavier than, lighter than]; capacity and volume [for example, full/empty, more than, less than, half, half full, quarter]; and time [for example, quicker, slower, earlier, later]
Measure and begin to record lengths and heights, mass/weight, capacity and volume, and time (hours, minutes, seconds)
Recognise and know the value of different denominations of coins and notes
Sequence events in chronological order using language [for example, before and after, next, first, today, yesterday, tomorrow, morning, afternoon and evening]
Recognise and use language relating to dates, including days of the week, weeks, months and years
Tell the time to the hour and half past the hour and draw the hands on a clock face to show these times

Objectives from the National Curriculum in England, © Crown copyright, used under the Open Government Licence v3.0.

A worked example: showing half past 4 on a clock

Draw the hands on a clock face to show half past 4.

Remember the two hands. The short hour hand tells you which hour it is, and the long minute hand tells you how far through the hour we are.
Start with 4 o’clock. The minute hand points straight up at the 12 and the hour hand points exactly at the 4.
```
4 o’clock
minute hand: at 12
hour hand: at 4
```
Half past means half an hour has gone by. The minute hand travels halfway round the clock, from the 12 to the 6, so it points straight down.
```
half past 4
minute hand: at 6
```
In that half hour the hour hand has also moved on. It started on the 4 and is now halfway between the 4 and the 5.
```
hour hand: between 4 and 5
```
Check. The hour hand has gone past the 4 but has not reached the 5, so the hour is still 4. With the minute hand at 6 that makes half past 4, not half past 5.

Half past 4: the long minute hand points at the 6, and the short hour hand is halfway between the 4 and the 5.

Common mistakes and how to help

Measuring with gaps, or without starting at the end of the object

Children focus on counting the units and forget that each one must touch the next. With a ruler they often start at 1 instead of 0, or begin at the end of the ruler rather than the zero mark.

What helps: Line up the object with the zero mark, or with the first cube, and check that each unit touches the next with no gaps or overlaps. Ask “Where does it start?” before every measurement.

Thinking bigger means heavier, or taller means more

Size is easy to see, but weight and capacity are not. A big balloon seems heavier than a small stone, and a tall thin glass looks as if it holds more than a short wide one.

What helps: Test it. Hold the objects, use balance scales, and pour water from one container into another to see which holds more. Ask your child to predict first, then check and discuss the surprise.

Reading half past 4 as “half past 5”, or mixing up the two hands

At half past the hour the hour hand sits close to the next number, so children read the number it is nearest. The two hands also look alike at a glance.

What helps: Say that the short hand tells the hour and the long hand tells the minutes. At half past, point out that the short hand has not yet reached the next hour. Then show 5 o’clock, when it has.

Assuming a bigger coin is worth more

In many other settings bigger means more. The 2p coin is larger than the 5p, and the 10p is larger than the 20p, so size does not give the value.

What helps: Handle real coins and sort them by value, not size. Ask “Which would you rather have, one 2p coin or one 5p coin?” and let your child lay them out in order of worth.

How to help at home

Measure with what you have. Measure a table, a book or a toy with hand spans, pencils or building bricks, then with a ruler. Ask “Which is longer? How much longer?” and remind your child to start at the same edge each time.
Weigh and pour in the kitchen. Compare tins, bags of flour and fruit by holding them, then check on kitchen scales. At the sink, with an adult close by, pour water between cups, jugs and bowls and ask which holds more, and when something is half full.
Run a pretend shop. Use real coins to price items at 1p to 20p, and let your child name each coin and say its value. Ask which coin is worth the most and which the least, then swap roles with your child as the shopkeeper.
Talk about the clock. Point out o’clock and half past times during the day, such as lunch at half past twelve. Make a clock from a paper plate with two paper hands and ask your child to show the times you call out.
Use the calendar and routines. Say today’s day and month every morning and ask what day it was yesterday and will be tomorrow. Put the day’s events in order: first breakfast, next school, then lunch, and after that, home.

Leads on to

Year 2: Standard units, money and time

Everything in Year 1 maths

Updated 20 October 2026.