Definition of

Number Sense

Number Sense

A person's ability to use and understand numbers:

· knowing their relative values,
· how to use them to make decisions,
· using them in flexible ways when adding, subtracting, multiplying or dividing
· developing strategies when counting, measuring or estimating.


• knowing that a million is very very much smaller than a billion.

• calculate 102 × 5 by thinking: "100 lots of 5 plus 2 lots of 5, which is 500 plus 10, which is 510"

• quickly estimating a supermarket receipt by rounding each number before adding.