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What is a prime number?

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Prime numbers are special numbers, greater than 1, that have exactly two factors, themselves and 1.

19 is a prime number. It can only be divided by 1 and 19.

9 is not a prime number. It can be divided by 3 as well as 1 and 9.

The prime numbers below 20 are:

2, 3, 5, 7, 11, 13, 17, 19

The number 1 is not a prime number as it only has one factor.

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Watch: Prime numbers

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Teaching resources

Looking for even more resources to help engage students in your maths lessons? Get stuck into Prime numbers, composite numbers and factors with the Prime Suspects in this animated short clip.

91热爆 Teach has thousands of free, curriculum-linked resources to help deliver lessons - all arranged by subject and age group.

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NEW! Play Guardians: Defenders of Mathematica - the winter update. game

It's Mathematica as you鈥檝e never seen it before, with all-new festive backgrounds and costumes. Available for a limited time only. Use your maths skills to save the day before it's too late!

NEW! Play Guardians: Defenders of Mathematica - the winter update
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