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Prime Numbers

A Prime Number is a number that can only be divided by 1 and itself

e.g. 3, 17 or 29

Listen to the song to recap the  prime numbers up to 100. 

Can you guess how many there are?

Prime Numbers up to 100

Let’s recap! The activity below will help you learn the sequence of prime numbers.

Main Activity

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Main Activity


There are some simple rules to find out the 25 prime numbers.

Follow the step by step rules, colouring each number as you go.

When you have finished there should be 25 white squares… these are your prime numbers!

Too many or too few? Try to figure out where you went wrong before checking using the answer grid below!



a) Colour in 1 as it is not a prime number (it only has one factor)


b) Colour in multiples of 2 (but not 2)


c) Colour in multiples of 3 (but not 3) - to check if larger numbers are factors of 3, add the digits together. If the total is a multiple of 3, then the number will be too. E.g. 87 8+7=15 (15 is a multiple of 3 so 87 is too)


d) Colour in multiples of 5 (but not 5)


e) Colour in multiples of 7 (but not 7)




Think you’ve mastered prime numbers? Have a go at the challenge quiz below!