Signs (directed numbers)

Steps

1. Change "minus a negative" to "plus": a − (−b) = a + b.
2. Multiply or divide: same signs give +, different signs give −.
3. Do brackets and powers first; (−3)² = 9 but −3² = −9.

Why: subtracting a debt is the same as gaining money.

Want to check an answer? Fraction calculator shows every step.

Worked examples

−3²     = −9          only the 3 is squared
(−2)³   = −8          so − (−8) = + 8
(−4)(−5) = 20         same signs give +
−9 + 8 + 20 = 19

For the whole topic, read Number and algebra basics: key points, common mistakes and how the DSE tests it.

Other methods in this topic