Every number has a partner that cancels it out completely — add them together and you get zero, every time. That partner is called the additive inverse, and finding it is delightfully simple: just flip the sign. The additive inverse of 5 is -5, the additive inverse of -12 is 12, and zero is its own partner. It sounds like a vocabulary word invented to torture algebra students, but the idea is everywhere once you notice it: a $50 deposit cancels a $50 withdrawal, climbing 200 feet cancels descending 200 feet, and every subtraction problem is secretly an addition of an inverse (8 - 3 is really 8 + (-3)). Type your number into the Number field and the Additive Inverse result appears instantly. Try 5, then try -12, then try 0 to see each case. Understanding inverses is also the doorway to solving equations — isolating x almost always means adding the inverse of whatever is stuck to it.

With the pre-filled defaults — Number 5 — the Additive Inverse Calculator returns Additive Inverse -5.0000. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.