*The National Curriculum states that pupils should be taught to:*

*identify multiples and factors, including finding all factor pairs of a number and common factors of two numbers.**know and use the vocabulary of prime numbers, prime factors and composite (non-prime) numbers.**establish whether a number up to 100 is prime and recall prime numbers up to 19.*

Therefore, 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 between 1 and 100.

- First, we coloured in 1, because all prime numbers are greater than 1.
- Number 2 is a prime number.
So we kept it, but coloured in all the multiples of 2 (i.e even numbers).*In fact 2 is the only even prime number.* - 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!

**All the coloured in numbers are called COMPOSITE NUMBERS!**

*There you have it. There are 25 prime numbers between 1 and 100! Well done Year 5.**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.