# Subtraction of Integers

Subtraction is just the inverse of addition. To subtract integers, you just have to change the subtraction problem into an addition problem, then perform the following steps:

**Keep**the sign of the first integer.**Change**the subtraction (-) to addition (+).**Change**the sign of the second integer. (+ becomes – and – becomes +)- Use the addition rules. (You can use a number line.)

**Example #1: 8 - (-2) = 10**

** **To subtract -2 from 8, perform the four steps above. Perform the first three steps “keep, change, change” in order to use the rules for addition, then find the answer by using the number line.

Using the second expression,** **8 + (+2),** **move 8 units to the right from zero since 8 is positive, and from move 2 units to the right again until the mark 10 is reached.

**Example #2: (-5) - (4) = - 9**

** **To subtract from -5, perform the four steps above. Perform the first three steps “keep, change, change” in order to use the rules for addition, then find the answer by using the number line.

Using the second expression,** **-5 + (-4),** **move 5 units to the left from zero since 5 is negative, and from -5 move 4 units to the left again until the mark -9 is reached.

Example #3: (-3) - (-7) = 4

** **To subtract -7 from -3, perform the four steps above. Perform the first three steps “keep, change, change” in order to use the rules for addition, then find the answer by using the number line.

Using the second expression, -3 + (7),** **move 3 units to the left from zero since 3 is negative, and from -3 move 7 units to the right until the mark 4 is reached.