45 = 5 \times 9\) and so is not prime. 43 is prime as the only factors of 43 are 1 and 43. The first square number is 1 because \(1 \times 1 = 1\). The second square number is 4 because \(2 \times ...

We look at how to decide whether a natural number is prime or composite by looking for proper factors.The importance of being methodical is emphasised. Ends with a square roots sketch illustrating ...