Adding in columns
3471
+2156
5627
Addition and Subtraction
In Year 4, children add and subtract numbers with up to four digits using the formal column methods, lining up thousands, hundreds, tens and ones and carrying or exchanging where they need to. They also learn to estimate the answer first by rounding, and to use the inverse operation to check their working. This is the year written arithmetic becomes secure, and it sits under almost everything that follows, from money and measures to the longer word problems they meet later in school.
Practise Addition and Subtraction
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
The column method
Two four-digit sums set out in columns, like the ones you will practise: one that carries and one that exchanges.
Taking away in columns
6482
-1356
5126
For grown-ups
Column addition and subtraction is really one idea applied carefully, place value by place value: when a column makes ten or more it carries on, and when the top digit is too small it exchanges with the column next door. Two habits turn that method into a dependable skill, and Year 4 builds both: estimate by rounding before you start so you know roughly where the answer should land, and check with the inverse afterwards so a slip shows up rather than slipping through. Children also meet two-step problems, where they have to work out which operations to use and in what order before any of the arithmetic begins. Get this secure now and the heavier calculations of Years 5 and 6, decimals, measures and multi-step reasoning, rest on solid ground.
What is in this topic
- Adding and subtracting numbers with up to four digits using the column method
- Estimating an answer by rounding before working it out
- Using the inverse to check an answer is right
- Finding the missing number in a calculation
- Two-step addition and subtraction word problems set in everyday situations
How to help at home
Confidence with four-digit column work grows from a steady routine, not from rushing. The biggest gains come from two habits done every time: estimate before you start, and check with the inverse after. Build those in early and the carrying and exchanging look after themselves.
- Estimate first, every single time, before touching the columns. Round each number to the nearest hundred and add roughly: for 3471 + 2156, that is about 3500 + 2200 = 5700, so the real answer of 5627 should land near there.
- Line the digits up by place value, ones under ones, and work right to left. In 3471 + 2156 the ones 1 + 6 = 7, the tens 7 + 5 = 12 so write 2 and carry 1 into the hundreds, which keeps the carrying tidy and visible.
- Check the answer with the opposite sum. After 6482 - 1356 = 5126, add it back: 5126 + 1356 should return 6482, and it does, which proves the exchanging was done correctly.
- Practise finding the missing number by turning it into a subtraction. For 3471 + ? = 5627, work out 5627 - 3471 = 2156, so the inverse becomes a reliable way in rather than guesswork.
Where children get stuck
The most common slip is forgetting to carry the extra ten, or writing the whole two-digit total in one column. When the tens make 7 + 5 = 12, only the 2 belongs in the tens column and the 1 must move on to the hundreds. Saying the carried digit out loud, "carry the one", as they write a small 1 above the next column makes it a deliberate step rather than something quietly dropped.
The other frequent wobble is in subtraction, when the top digit is smaller than the bottom one and a child simply takes the little from the big regardless of order, turning 6482 - 1356 into a muddle. The fix is to spot it early and exchange: when you cannot take 6 from 2 in the ones, exchange one ten for ten ones so the 2 becomes 12, then carry on. Asking "is the top number big enough, or do we need to exchange?" before each column heads the mistake off.