中文（繁體）
中文（简体）
English
Primary 6 Maths: Surface Area of Solids — Practice Paper 3 (10 Questions)
Primary 6 Maths: Surface Area of Solids — Practice Paper 3 (10 Questions)
Paper 3 moves from the six-face formula to real situations: an open box with five faces, an edge recovered from a surface area, and the area gained or lost when solids are joined or cut.
Quick answer Ten questions, about 22 minutes. Items 01 to 04 apply the cuboid and cube formulas; items 05 to 07 cover an open box, an edge from a surface area and joined cubes; items 08 and 09 compare longer edges and a cut; item 10 redoes volume used as surface area.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 questions |
| Suggested time | 22 minutes |
| Difficulty mix | Foundation 4 · Intermediate 3 · Challenge 2 · Error redo 1 |
| Chapter | Chapter: Primary 6 Maths: Surface Area of Solids — Tutor Lesson Plan |
| Level | Primary 6 |
02 Questions (10 items)
- FoundationA cuboid is 6 cm by 4 cm by 3 cm. What is its surface area?
- FoundationA cube has edges of 5 cm. What is its surface area?
- FoundationFind the surface area of a cube with 10 cm edges, and of one with 1 m edges.
- FoundationA cuboid is 8 cm by 5 cm by 2 cm. What is its surface area?
- IntermediateAn open-top box is 20 cm long, 15 cm wide and 10 cm high. What area of card is needed?
- IntermediateA cube has a surface area of 216 cm². Find its edge and its volume.
- IntermediateTwo 5 cm cubes are joined to form a cuboid. How much surface area is lost?
- ChallengeOne cube has a surface area of 96 cm². A second cube has edges 1 cm longer. What is the difference in surface area?
- ChallengeA 12 cm by 8 cm by 5 cm cuboid is cut in half along its length. How much does the total surface area increase?
- Error redoA student writes “surface area of a 6 by 4 by 3 cuboid = 6 × 4 × 3 = 72 cm²”. What is the correct surface area?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | 108 cm² | Faces: 24, 18 and 12; doubled the total is 108 cm². |
| 2 | 6 × 25 = 150 cm² | A cube has six equal faces of 25 cm², so 150 cm² in all. |
| 3 | 600 cm²; the 1 m cube is 6 m² | 10 × 10 = 100, times 6 is 600 cm²; a 1 m cube has six 1 m² faces, so 6 m². |
| 4 | 132 cm² | The three face areas are 40, 16 and 10; their total 66 doubled is 132 cm². |
| 5 | Base 300 plus four sides 700 gives 1000 cm² | Five faces only: base 300, two 200 cm² sides and two 150 cm² ends, total 1000 cm². |
| 6 | Edge 6 cm, volume 216 cm³ | Each face is 36 cm², so the edge is 6 cm and the volume 216 cm³. |
| 7 | 50 cm² less (from 300 cm² to 250 cm²) | Separately 2 × 150 = 300 cm²; joined it is 10 by 5 by 5, giving 250 cm² — two 25 cm² faces are hidden. |
| 8 | Edge 4 gives 96 cm² and edge 5 gives 150 cm², a difference of 54 cm² | 96 ÷ 6 = 16, so the edge is 4 cm; the second cube has 6 × 25 = 150 cm², a difference of 54 cm². |
| 9 | 80 cm² more (from 392 to 472) | The original is 392 cm²; each half is 236 cm², so the two halves total 472 cm² — two new 8 by 5 faces add 80 cm². |
| 10 | The correct area is 108 cm²; 72 cm³ is the volume | 6 × 4 × 3 = 72 cm³ is the volume; surface area adds the three face areas and doubles them, giving 108 cm². |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.
