In a chess tournament Ishan's rating changed by −40 points in the first round. In the second round it changed by the additive inverse of that amount. What was his total rating change over the two rounds?

Subtraction of integers is just adding the **opposite**: a − b = a + (−b). So 5 − 8 = 5 + (−8) = −3. And 5 − (−8) = 5 + 8 = 13. The 'minus minus' that looks confusing in symbols is simply: subtracting a negative is the same as adding its positive twin. Always rewrite subtraction as addition of the opposite — it removes every sign-error trap.