Adding in columns
248365
+137492
385857
Addition and Subtraction
By Year 6, children add and subtract large numbers with confidence, both in their heads and on paper. They reach for a mental strategy when the numbers suit it and fall back on a careful column method for the rest, and they learn the order of operations, often called BIDMAS, so they know which part of a calculation to settle first.
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 large sums set out in columns, the kind you still reach for when the numbers get big.
Taking away in columns
615280
-342716
272564
For grown-ups
Knowing what to calculate first is what turns a string of numbers into a single right answer, and brackets become a way to say "do this part before the rest", deliberately changing which step comes first. Estimating by rounding before working anything out is the habit that catches the slips, a quick check on whether an answer even looks sensible. Calculations like these rarely arrive on their own at this stage, so children also work through longer problems that fold addition, subtraction, multiplication and division into several steps. That is the kind of reasoning that sits under the arithmetic and algebra of secondary school.
What is in this topic
- Mental addition and subtraction with large numbers
- Written column methods for large numbers
- The order of operations (BIDMAS), including placing brackets
- Using estimation to check whether an answer is sensible
- Multi-step problems mixing all four operations
How to help at home
By Year 6 the column method is mostly secure, so the real work is reliability under pressure: setting sums out neatly, knowing what to calculate first, and pausing to ask whether an answer is even sensible. Short, regular sessions that include a quick estimate every time build that habit far better than one long push.
- Insist on an estimate before the exact sum, every time. Before working out 4980 + 3120, ask them to round and guess: 5000 + 3000 is about 8000, so an answer of 810 or 81000 is clearly wrong and worth re-checking.
- Drill the order of operations on tiny sums, not just long ones. Write 2 + 3 x 4 and ask what comes first: the multiply, giving 2 + 12 = 14, never 5 x 4 = 20. Do three or four of these a day until it is automatic.
- Show how brackets change the answer. Compare 5 + 6 x 2, which is 5 + 12 = 17, with (5 + 6) x 2, which is 11 x 2 = 22, so they feel that brackets are a way to say 'do this part first'.
- Keep columns lined up with one digit per box. In a sum like 615280 - 342716, a single misaligned digit throws everything off, so squared paper or a ruled grid prevents most slips before they happen.
Where children get stuck
The most common mistake is working strictly left to right, so a child reads 20 - 4 x 3 and does 20 - 4 = 16, then 16 x 3 = 48. The fix is to make them hunt for the multiply or divide first and underline it: here 4 x 3 = 12, then 20 - 12 = 8. Spotting the operation before touching a number breaks the left-to-right habit.
The other frequent wobble is in subtraction, where children subtract the smaller digit from the larger in each column regardless of which is on top, turning 615280 - 342716 into nonsense in the ones. Reground them in exchanging: when the top digit is smaller, exchange one from the column to the left, so 0 take away 6 becomes 10 take away 6, and the digit to the left drops by one.