Question

What number should be added to 77 to make the sum 0?

Answer 1

You should add -77 to 77 because it will cancel out.

Answer 2

Additive inverses are two numbers that add to 0.
0 is the additive inverse of 0 since 0 + 0 = 0.
For all positive and negative numbers, to find the additive inverse of a number, change its sign.
The additive inverse of 1 is -1.
The additive inverse of 100 is -100.
The additive inverse of -9.5 is 9.5.
In this problem, the additive inverse of 77 is -77.