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 ...

Fermat—most famous for his mysterious “ last theorem ,” which vexed experts for decades—contributed all kinds of useful things to the world of science in his lifetime. For example, he laid the ...

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 ...

Prime numbers are intriguing numbers that are greater than 1 and can be evenly divided only by themselves and 1. The four smallest prime numbers are 2, 3, 5 and 7. Next comes 11, which is quite a ...