11.11.20
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.