Solve problems involving multiplication and division, including using their knowledge of factors and multiples, squares and cubes

What this means, in plain words

A multiple of a number is what you get when you multiply it by a whole number, so 12 is a multiple of 3.

A factor is a whole number that divides into another exactly, with nothing left over.

This is problem solving: the maths is met inside a situation, so the first job is working out which operation the question is asking for.