Written methods, explained

The written methods for numbers too big to work out in your head. Add and subtract one column at a time, carrying and exchanging as you go; multiply by one digit at a time and add the rows; or divide, multiply, subtract and bring down. Decimals need only one extra step each, and it is all about where the point goes.

Questions people ask

In what order are these usually learned?

Addition and subtraction come first, and each later method uses them. Every row of a long multiplication is added up at the end, and every step of a long division is a subtraction.

Do I need to know the times tables first?

For multiplication and division, mostly, yes. Both methods break one big calculation into lots of small ones, and every small one is a times-table fact. If you have to work out 7 × 8 each time, you tend to lose your place in the method.

Which comes first, long multiplication or long division?

Long multiplication. Long division uses it at every step, because each digit of the answer is multiplied by the divisor and the result taken away.

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