Expressions, order of operations and grouping symbols
Answers are for parents and teachers.
1
Work out 14 + 18 ÷ 3 − 2 × 4.
18 ÷ 3 = 6 and 2 × 4 = 8. Then 14 + 6 = 20 and 20 − 8 = 12.
2
Work out 4 × (7.5 − 2.5) + 6.
7.5 − 2.5 = 5; 4 × 5 = 20; 20 + 6 = 26.
3
Place parentheses in 5 + 3 × 2 to make 16.
(5 + 3) × 2 = 8 × 2 = 16.
4
Rahma has 100 LE. She buys 3 kg of bananas at 15 LE per kg and a pineapple for 20 LE. Write an expression for the money left and find it.
100 − (3 × 15 + 20) = 100 − (45 + 20) = 100 − 65 = 35 LE.
5
Seif says 10 − 2 × 3 = 24. Find his mistake and the right value.
He subtracted first (10 − 2 = 8, then 8 × 3 = 24). Multiplication comes first: 2 × 3 = 6, and 10 − 6 = 4.