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LC: To understand and identify prime numbers

So far, we have done well with prime numbers generally. Today's lesson is looking at prime numbers again.


Remember, prime numbers have only two factors - 1 and itself. Therefore 7 is a prime number because I can only divide it by 1 and 7 and the answer is a whole number.


Is 18 a prime number? NO, because I can divide 18 by 1, 2, 3, 6, 9 and 18. 


1 x 18 = 18

2 x 9 = 18

3 x 6 = 18


So 18 has six factors.

Numbers that are not Prime Numbers are know as Composite Numbers. So 7 is a composite number because it only has two factors - 1 and 7 - it's a prime number!
When you have had a go at the Guided Practice questions, complete the following worksheet. If you are working at home, you do not have your Maths No-Problem book, so you need to neatly copy the questions into your Home Learning book.