In Numeracy, Year five have been learning about multiples, factors, prime numbers and prime factors. Here, the children are creating a table that will help them identify prime numbers less than 100.
- First we coloured in 1, because all prime numbers are greater than 1.
- Number 2 is a prime number. In fact it is the only even one. So we kept it, but coloured in all the multiples of 2 (i.e even numbers).
- Number 3 is also a prime, so again we kept it and coloured in all the multiples of 3.
- The next number not coloured in was 5 (because 4 was already coloured in), so we kept it and coloured in all the multiples of 5.
- The final number left in the first row was 7 (it’s prime so we kept it) and coloured in all the multiples of 7.
- FINISHED! All the ‘surviving’ numbers that are not coloured in on the grid are PRIME NUMBERS!
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![](http://www.stmichaels1871.org.uk/blog/wp-content/uploads/2021/11/IMG_1070-1024x768.jpg)
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Did you know that whole numbers that are not prime numbers are called composite numbers? We hope you have learnt something new from our blog today.