Addition and Subtraction
2-2Addition on a Number Line
Overview
Adding a positive moves right; adding a negative moves left. Start at the first number and move by the second.
Key ideas
- (+) + (+) → move right.
- (+) + (−) → move left.
- The sum is your stopping point.
Worked examples
Example 1
Problem. Find 3 + (−5) on a number line.
Solution. Start at 3, move 5 left → −2.
Example 2
Problem. Find −2 + 6.
Solution. Start at −2, move 6 right → 4.
Practice
Try each one. Click Show answer when ready.
- 1.
−4 + 7
- 2.
5 + (−9)
- 3.
−3 + (−2)
Challenge problems
A little tougher — great for test prep. Click Show answer when ready.
- 1.
Show 5 + (−3) on a number line and state the result.
- 2.
What number must you add to −4 to get 1? Use a number line to explain.