Try some yourself
Activity 30
Carry out the following calculations, without your calculator.
(a) 3 × (60 + 70).
(b) (3 × 60) + 70.
(c) (70 − 60) ÷ 5.
Check your answers using your calculator.
Answer
(a) 3 × (60 + 70) = 3 × 130 = 390.
(b) (3 × 60) + 70 = 180 + 70 = 250.
(c) (70 − 60) ÷ 5 = 10 ÷ 5 = 2.