Primary 4 Mathematics · Chapter 13 · Answers and explanations

Lesson 13.6: Word Problems: Nets and Solids (answers)

Section A · Multiple choice 4 marks

1. Each face of a cube-shaped box is a square with sides of 4 cm. What is the total area of cardboard for the box?1 mark

(A) 64 cm²(B) 24 cm²(C) 16 cm²(D) 96 cm²

Answer: (D) 96 cm²One face: 4 × 4 = 16 cm². 6 faces: 6 × 16 = 96 cm².

2. A cuboid box is 5 cm long, 3 cm wide and 2 cm high. What is its total surface area?1 mark

(A) 62 cm²(B) 30 cm²(C) 31 cm²(D) 124 cm²

Answer: (A) 62 cm²2 × (5 × 3) + 2 × (5 × 2) + 2 × (3 × 2) = 30 + 20 + 12 = 62 cm².

3. A cube-shaped box has a total surface area of 54 cm². What is the area of one face?1 mark

(A) 6 cm²(B) 9 cm²(C) 18 cm²(D) 27 cm²

Answer: (B) 9 cm²54 ÷ 6 = 9 cm².

4. Ali has drawn 4 squares of a net of a cube. How many more squares does he need?1 mark

(A) 1(B) 3(C) 2(D) 4

Answer: (C) 26 − 4 = 2 more squares.

5. Each face of a cube box is a square with sides of 10 cm. What is the total area of the 6 faces?1 mark

Answer: 600 cm²One face: 10 × 10 = 100 cm². 6 × 100 = 600 cm².

6. A cuboid box is 8 cm long, 3 cm wide and 2 cm high. What is the total area of its faces?1 mark

Answer: 92 cm²2 × 24 + 2 × 16 + 2 × 6 = 48 + 32 + 12 = 92 cm².

7. The total area of all the faces of a cube is 150 cm². What is the area of one face?1 mark

Answer: 25 cm²150 ÷ 6 = 25 cm².

8. How many faces does the net of a triangular pyramid have?1 mark

Answer: 4A triangular pyramid has 4 triangular faces.

9. Mina has drawn 3 squares of a net of a cube. How many more squares does she need?1 mark

Answer: 36 − 3 = 3.

10. A cuboid box is 10 cm long, 6 cm wide and 4 cm high. How much cardboard is needed to make the box?2 marks

Answer: 248 cm²2 × 60 + 2 × 40 + 2 × 24 = 120 + 80 + 48 = 248 cm².

11. A cube-shaped gift box has sides of 7 cm. How much wrapping paper is needed to cover all its faces?2 marks

Answer: 294 cm²One face: 7 × 7 = 49 cm². 6 × 49 = 294 cm².

12. The total area of all the faces of a cube-shaped box is 216 cm². What is the length of one side?2 marks

Answer: 6 cmOne face: 216 ÷ 6 = 36 cm². 6 × 6 = 36, so the side is 6 cm.

Shukr Learns · free practice for parents and children · original questions, not affiliated with any school or agency