N

near doubles

Addition or subtraction facts found by using doubles. For example, knowing 3 + 3 = 6 helps you know that 3 + 4 is one more or 7.

nickel

A coin equal to (or worth) 5 cents (5¢).

nonstandard unit of measurement

Units of measurement that are not part of a consistent way of measurement. For example, nonstandard units include hands, cubits, and arm spans because they are not the same for everyone.

noon

Twelve o'clock in the daytime.

number line

A line with numbers marked at regular intervals used for counting, adding, subtracting, or comparing numbers.

number sentence

A number sentence uses numbers and symbols instead of words to describe a math operation. For example, 5 + 2 = 7 and 9 − 2 = 7 are number sentences.