Task# Integers on the Number Line 2

Illustrative MathematicsVaries

The goal of this task is to study, with a number line, why it makes sense for a whole number a that -(-a) = a. The negative sign preserves the distance from 0 but switches the direction from 0. There are only two directions to go on the number line: left and right. Therefore, if we switch directions twice this will bring us back to our original direction from 0.