Definition
Number
A number is a mathematical idea that tells how many, how much, which position, or what value.
What it means
You cannot point to the number eight itself; you point to ways of showing it. Eight counters, the word eight, the numeral 8, the expression 5 + 3, and the point 8 on a number line all represent the same number.
Remember it
One number can wear many forms and still keep the same value.
Example
Eight counters tell how many objects there are. The numeral 8 and the word eight write that value, 5 + 3 names it with an expression, and a marked point shows its position on a number line. These different forms all represent the number eight.
Watch for
The written symbol 8 is a numeral, which represents the number eight; the mark on the page is not the abstract number itself.
Common mix-up
A string of digits can be used as a label, such as a bus route or telephone number, without telling a quantity or measurement.
Exact meaning
A number is an abstract mathematical value used to describe quantity, order, measure, label, or relationships. A number can be represented by numerals, words, objects, points on a number line, or equivalent expressions without being identical to any one representation.