To add a positive number, move right on the number line. To subtract a positive number, move left. So −2 + 7 = 5 and 3 − 8 = −5.
Adding a negative number is the same as subtracting: 6 + (−4) = 6 − 4 = 2. Subtracting a negative number is the same as adding: 5 − (−3) = 5 + 3 = 8. Two signs next to each other that are the same make a plus; two that are different make a minus.
Worked example
−10 − 5 =
- Start at −10 and move 5 to the left.
- You land on −15.
Answer:−15
Key words
- positive
- greater than zero
- negative
- less than zero
- number line
- a line showing numbers in order
Practise this
New questions every time.
Common Core-referenced: 7.NS.A.1