Use place value, known and derived facts to multiply and divide mentally, including: multiplying by 0 and 1; dividing by 1; multiplying together 3 numbers

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.

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.