Add & Subtract with Negative Numbers

You can create a vertical number line or a horizontal number line. A vertical line has 0 in the middle, the positive numbers are above 0, and the negative numbers are below 0. A horizontal number line has 0 in the middle with the positive numbers to the right of 0 and the negative numbers to the left of 0.

9 units above 0.

12 units below 0.

6 units to the right of 0.

9 units to the left of 0.

A number line shows that the solution to 5 + 7 is 12. Start at 5 and jump 7 units to the right, to 12.

A number line shows that the solution to –5 + (–8) is –13. Start at –5 and jump 8 units to the left, to –13.

A number line shows that the solution to +3 – 7 is –4. Start at 3 and jump 7 units to the left, to –4.

A number line shows that the solution to –4 + (–3) is –7. Start at –4 and jump 3 units to the left, to –7.

A number line shows that the solution to 4 – (–5) is 9. Start at 4 and jump 5 units to the right, to 9.