Register Now!

Search Skwirk

Adding and subtracting directed numbers

Directed numbers are numbers which are either positive or negative.

Directed numbers can be added and subtracted together just like normal positive integers - signs, however, become very important because each directed number has its own positive or negative sign.

It is helpful to use a number line to add and subtract directed numbers.

There are three steps to adding and subtracting directed numbers:

Step 1: Find the starting position on the number line - this will be the first number in the calculation.

Step 2: Identify the direction of travel on the number line - this is determined by the signs that appear in the calculation.

If two adjacent (next to each other) signs are the same, then they equal a positive.

For example, 8 - (-8) = 8 + 8
= 16

If two adjacent signs are different, then they equal a negative.

For example, 8 + (-8) = 8 - 8
= 0

Step 3: Move the number of places on the number line required by the calculation - this will be the second number in the calculation.


Pop Quiz

The more you learn - the more you earn!
What are points?Earn up to points by getting 100% in this pop quiz!

Question 1/5

1. Choose the FALSE equation.

43 - (-18) = 25

-18 - (-32) = 14

-30 + (-26) = -56

64 + (-16) = 48

ToolBox