1. Multiples, factors and primes
N1.3 Support Starter
How many different pairs of whole numbers can you find
which have 24 as their product?
Is the following statement true?
No two whole numbers have the same sum and product.
Preamble
A moderately straightforward activity for small groups or individuals which gives pupils the opportunity to use their knowledge of multiplication tables. If appropriate, the idea of working systematically to find factors could be introduced at an informal level. The activity may be extended to other numbers such as 36. Pupils may need to be reminded about what a product is.
Possible content Simple multiplication, vocabulary of number.
Resources None.
Solutions/Notes
1 × 24, 2 × 12, 3 × 8, 4 × 6
The opportunity may arise as to the legitimacy of allowing 1 × 24 and to discuss whether, for example, 3 × 8 is different from 8 × 3.
Statement: 2 and 2 are the only numbers whose sum and product is the same.