Basic facts

The sums (additions) and products (multiplications) of all pairs of whole numbers from 0 to 9. These need to be memorised. The sums of single-digit numbers added to 10 can be called ‘teen facts’. The sums obtained by adding single-digit numbers to whole numbers that are multiples of 10 can be called ‘decade facts’. The facts for the sums of multiples of 10, 100, etc. (for example, 30 + 40, 500 + 600) are sometimes called ‘place value facts’.