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Maths tricks

Maths tricks and strategies, step by step

21 ways to work things out in your head and on paper. Each one has a worked example you can tap through, a picture that shows why it works, and five fresh practice questions.

Make ten

Adding and subtracting

Make ten

Look for two numbers that make 10, and add them first.

Ages 5–8

Near doubles

When two numbers are next to each other, double the smaller one and add 1.

Ages 6–8

Bridging ten

Jump to the next ten first, then add what is left.

Ages 6–9

Partitioning

Split numbers into tens and ones, add each part, then put them back together.

Ages 7–10

Round and adjust

Add a nearby round number instead, then adjust by the difference.

Ages 8–11

Multiplying and dividing

The nines trick

To multiply by 9, multiply by 10 and take one lot away.

Ages 8–10

Chunking

Divide by taking away big chunks you know, like 10 lots, then count the chunks.

Ages 9–12

Fractions and percentages

Methods, rounding and order

Column addition

Line up the digits by place value, add from the ones, and carry when a column makes 10 or more.

Ages 8–11

Column subtraction

Subtract from the ones; when the top digit is too small, exchange 1 from the next column.

Ages 8–11

Bar models

Draw the problem as bars so you can see what to work out.

Ages 7–13

Rounding

Find the two tens (or hundreds) a number is between, and pick the nearer one.

Ages 7–11

Estimating

Round the numbers to work out roughly what the answer should be.

Ages 8–13