Decimals
In Year 4 your child meets decimals alongside the fractions work, learning that numbers can carry on past the decimal point. They count in tenths and hundredths, write fractions like a half or a quarter as decimals, see what happens when a number is divided by 10 or 100, and begin using decimals in everyday money and measurement. It is an important step that underpins much of the maths to come, from place value to handling pounds and pence with confidence.
Practise Decimals
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
Tenths and hundredths
The whole grid is 1, and each small square is one hundredth. Thirty shaded squares show 0.30, the same as 3 tenths.
For grown-ups
Decimals click once a child sees they are simply place value carried on past the ones, not a brand new kind of number, so each digit still means ten times less as it moves to the right. This year that grows into comparing numbers with up to two decimal places, rounding a one-place decimal to the nearest whole, and knowing the everyday equivalents by heart, a half as 0.5, a quarter as 0.25 and three quarters as 0.75. It is the reasoning that sits under all the money and measurement work to come, and it leads naturally into the percentages and more careful place value of later years.
What is in this topic
- Counting up and down in hundredths
- Writing tenths and hundredths as decimals, including a half, a quarter and three quarters
- Dividing a one or two digit number by 10 and by 100
- Rounding decimals with one decimal place to the nearest whole number
- Comparing decimals with up to two decimal places
- Solving money and measure problems with decimals
- Count up and down in tenths and read them off a number line
How to help at home
Decimals click once a child sees they are just place value carried on past the ones, not a brand new kind of number. Short, frequent practice with real prices and measures beats one long sitting, because the ideas need to settle through use.
- Anchor the three you must simply know by heart: a half is 0.5, a quarter is 0.25, three quarters is 0.75. Say them as a set each day until they come without pausing.
- Practise dividing by 10 and 100 with everyday numbers: 36 divided by 10 is 3.6, then 36 divided by 100 is 0.36. Point out the digits stayed as 3 and 6 and only shifted along.
- Use shopping to round and add money: ask 'is 4.6 nearer 4 or 5?' (it is 5), then total a 1.50 item and a 2.75 item to get 4.25, reading the answer as four pounds twenty-five.
Where children get stuck
The most common trip-up is thinking a longer decimal is a bigger one, so a child reads 0.07 as larger than 0.7. Line them up by place value, 0.70 against 0.07, and ask which column the first non-zero digit sits in: tenths beats hundredths, so 0.7 wins. Padding the shorter one with a zero makes the comparison fair.
The other wobble is not shifting the digit at all, so 7 divided by 10 is written as 7 (or 7.0, which is still just 7) instead of 0.7. Steady it by naming the columns out loud as each digit slides one place smaller: the 7 must leave the ones and land in the tenths, so a 0 holds the empty ones place and the answer is 0.7.