Use place value and number facts to solve problems

What this means, in plain words

Place value is the idea that a digit is worth a different amount depending on where it sits: the 4 in 40 is worth ten times the 4 in 4.

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.

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.