| Adding
a positive number can be thought of as moving to the right on a number
line. Moving to the left on a number line is the same as adding a negative
number. To find the sum of (+3) plus (-9), start at +3 on the number line
and move to the left nine units. The result is (-6). To find the absolute
value of a negative number using the number line locate the positive number
that is exactly the same distance from 0. |