what is a prime number?
what are the first ten prime numbers?
what are the prime numbers between 50 and 60?
what are factor pairs?
what are the factor pairs of 20?
what are factor trees?
what is the highest common factor (HCF)?
what is the HCF of 16 and 40?
what is the lowest common multiple (LCM)?
what is the LCM of 5 and 8?