Definition
Opposite numbers
A pair of numbers equally far from zero in opposite directions on the number line.
What it means
Start at zero and walk the same distance in opposite directions. The two landing numbers are opposites. Put them together in an addition and they cancel back to zero.
Remember it
Same distance from zero, different direction.
Example
The opposite of −12 is 12. They are both 12 units from zero, and −12 + 12 = 0.
Watch for
Zero is not paired with a different number: 0 is its own opposite because 0 + 0 = 0.
Common mix-up
The opposite of a number is not always negative. The opposite of −7 is 7.
Exact meaning
Opposite numbers are additive inverses: together they total zero, and each is the same distance from zero. Every number has one opposite; zero is its own.