Solve problems, including missing number problems, involving multiplication and division

What this means, in plain words

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.

Multiplication is repeated addition of equal groups. Division shares a total into equal groups, or works out how many groups fit.

Number work here is about how our number system is built, and about knowing what a number is worth rather than just how it is spelled.