Reason about the location of numbers to 20 within the linear number system

What this means, in plain words

A number line puts numbers in order along a line, evenly spaced, so larger and smaller can be seen rather than worked out.

This asks a child to say why, not just what. The sentence is the answer, and the number on its own is not enough.

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.