Subtracting a Negative

What happens when you subtract a negative number? Use the rule from the last lesson: subtracting is adding the opposite. The opposite of -4 is 4, so $2 - \left(-4\right)$ is $2+4$, which is 6. Two minus signs in a row become a plus.

On the number line, subtracting moves you left, and taking away a negative undoes a move left, so it moves you right. In money: if someone cancels a 4 dollar debt you owe, you are 4 dollars better off. The same holds below zero: $-7 - \left(-2\right)$ is $-7+2$, which is -5.