Try some yourself
Activity 21
Without using your calculator solve the following calculations.
(a) 3 + 5 × 2 = ?
(b) 12 − 6 + 6 = ?
(c) 6 + (5 + 4) × 3 = ?
(d) (3 + 5) ÷ 2 = ?
(e) 12 − (6 + 6) = ?
(f) 6 + 5 + 4 × 3 ÷ 2 = ?
Check your answers using a scientific calculator.
Answer
(a) 5 × 2 = 10
3 + 10 = 13.
(b) 12 − 6 = 6
6 + 6 = 12.
Remember that addition and subtraction belong to the same group and so the calculation is done from left to right.
(c) 6 + (5 + 4) × 3 = 6 + 9 × 3
9 × 3 = 27
6 + 27 = 33.
(d) (3 + 5) ÷ 2
8 ÷ 2 = 4.
(e) 12 − (6 + 6) = 12 − 12 = 0.
(f) 6 + 5 + 4 × 3 ÷ 2 = 6 + 5 + 6 = 17.