Adding Several Integers

A long sum of integers is worked like any long sum: left to right, one step per line. Take $6 + \left(-10\right) + 8 + \left(-1\right)$, which can also be written $6-10+8-1$. First 6 + (-10) is -4, giving $-4+8-1$. Then -4 + 8 is 4, giving $4-1$. Then 3.

There is a second route: gather the positives and the negatives. The positives 6 and 8 make 14. The negatives -10 and -1 make -11. Then $14-11$ is 3. Both routes give the same answer because a sum can be added in any order, and the second one has only a single sign change at the end.

Either way, read each minus sign as belonging to the number after it. In $6-10+8-1$ the numbers being added are 6, -10, 8 and -1. That is what lets you move them around, and it stops the slip of subtracting the 8 along with the 10.