A brighter way to learn

Year 3

Measurement

Year 3 measurement is all about reading scales and comparing measures. Children measure length, mass and capacity, reading a ruler, a set of weighing scales and a measuring jug, then compare, add and subtract the amounts.

Practise Measurement

Have a guess, even if you're not sure. Get one wrong and we'll show you why, so every miss is a chance to learn.

Timed practice

The same practice, just with a gentle clock. Pick a length and see how many you can answer.

Good to know

Each card shows a swap: how many small units fit inside one bigger one.

LengthHow long
10mm1cm
100cm1m
MassHow heavy
1000g1kg
CapacityHow much fits
1000ml1litre

For grown-ups

Each question shows the instrument to read, so your child practises lining up with the marks and working out the values in between. Reading a scale accurately is a skill that carries straight into science as well as maths.

What is in this topic

How to help your child with measuring

Measurement clicks when it is real and hands-on, so reach for a ruler, the kitchen scales and a measuring jug rather than the worksheet.

  • Read scales together on real instruments. Find the small marks between the numbers on a ruler, scale or jug, and count them up one by one so a mark is never just guessed.
  • Practise the swaps both ways. There are 100 cm in 1 m, so a piece of string that is 1 m 20 cm long is 120 cm, and 250 cm is 2 m 50 cm.
  • Line up measures before adding or subtracting. To add 1 cm and 5 mm, turn the 1 cm into 10 mm first, then 10 mm plus 5 mm is 15 mm.
  • Estimate first, then check. Ask how heavy a tin of beans is or how tall a chair is, guess, then measure, so the units start to mean something.

Where children get stuck

The biggest trip-up is mixing up the swaps, because length does not behave like mass and capacity. It is tempting to think 100 mm make 1 cm to match the 100 cm in a metre, when actually only 10 mm make 1 cm. The reference card pins this down: keep saying 10 mm in a cm, 100 cm in a metre, and let the two numbers sit side by side so the difference sticks.

The other common wobble is just jamming the two numbers together, reading 1 m 5 cm as 15 cm instead of 105 cm, forgetting that the metre is worth 100 cm and not 1. Remind your child to swap the metres into centimetres first: 1 m 5 cm is 100 cm plus 5 cm, which is 105 cm, and then it can be added to or compared with any other length in centimetres without the units getting tangled.

More Year 3 maths

Shapes, Angles and LinesCharts and PictogramsTimes Tables and Division