Definition
Zero
Zero is the number for none; it is neither positive nor negative, and adding it changes nothing.
What it means
Zero can tell you there are no objects, mark a position on the number line, or show an empty place inside a numeral. In addition, zero leaves a number unchanged: 7 + 0 = 7. These are connected jobs of the same number.
Remember it
Zero can mean none, hold a place, and leave an addition unchanged.
Example
In 407, the 0 says there are no tens while keeping 4 in the hundreds place and 7 in the ones place. Without that placeholder, 47 would name a different number. Zero also leaves addition unchanged, so 407 + 0 = 407.
Watch for
Zero is neither positive nor negative. It is an even whole number, but division by zero is not defined.
Common mix-up
Zero is the number; 0 is the numeral used to write it. The same numeral can show none or hold an empty place, depending on context.
Exact meaning
Zero is the number that represents a quantity of none. It is neither positive nor negative, lies between −1 and 1 on the number line, is the additive identity, and its numeral 0 can hold an empty place in positional notation.