Negative numbers: times and divide
You learn to multiply and divide with negative numbers: work out the number first, then the sign.
How to work it out
- First work it out without the minus signs.
- Then count the minus signs: if there are two or zero the answer is positive.
- If there is exactly one put a minus in front of the answer.
13 × 4 = 122−3 × 4 = −12
A worked example
−3 × 4
- Work it out without the minus signs: 3 × 4 = 12.
- Count the minus signs: there is one.
- One minus sign gives minus, so the answer is −12.
More examples
−7 × (−2)
- Work it out without the minus signs: 7 × 2 = 14.
- There are two minus signs, so the answer is positive: 14.
20 ÷ (−5)
- Work it out without the minus signs: 20 ÷ 5 = 4.
- There is one minus sign, so the answer is −4.
−6 ÷ (−3)
- Work it out without the minus signs: 6 ÷ 3 = 2.
- There are two minus signs, so the answer is positive: 2.
Try it yourself
−40 ÷ 8 =
6 × (−7) =
Watch out
For −7 × (−2) you still put a minus in front of the answer: −14.
Count the minus signs. Two minus signs cancel each other out, so the answer is positive.
Tips
- Do the number first and then the sign: two separate steps.
- An even number of minus signs gives plus, an odd number gives minus.
Why it works
You work out the number just as you always do. The sign follows a fixed rule: two signs that are the same give plus, two different signs give minus. That way you only do one thing at a time.