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P1 Maths: 3D Shapes (10 Error-Correction Items)
P1 Maths: 3D Shapes (10 Error-Correction Items)
Ten error-correction items: fixing wrong face, edge and vertex counts, a cone treated as having no apex and a sphere with a flat face, plus glued cubes, a cut cube and working back from 18 edges.
Focus Name the wrong step first, then count faces, edges and vertices again before writing the answer.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 25 |
| Difficulty mix | Foundation 2 · Intermediate 3 · Challenge 3 · Error redo 2 |
| Chapter | Chapter: P1 Maths: 3D Shapes |
| Level | P1 Maths |
02 Questions (10 items)
- FoundationA student writes that a cube has 4 faces. What is wrong, and how many faces does a cube really have?
- FoundationHow many edges and how many vertices does a cuboid have?
- IntermediateHow many faces, edges and vertices does a cylinder have?
- IntermediateA triangular prism has 5 faces and 9 edges. How many vertices does it have?
- IntermediateHow many faces, edges and vertices does a square pyramid have?
- ChallengeThree equal cubes are glued in a row. How many square faces are on the surface?
- ChallengeA cube is cut in half by one flat cut. How many faces do the two pieces have altogether?
- ChallengeA prism has 18 edges. Which prism is it, and how many faces does it have?
- Error redoA student answers that a cone has 2 faces, 0 edges and 0 vertices. What is wrong, and what are the correct counts?
- Error redoA student says a sphere has one flat face and can stand still. What is wrong?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | A cube has 6 faces: top, bottom, front, back, left and right, not 4. | Count all six directions; four is only the number of side faces, so the top and bottom must be added. |
| 2 | A cuboid has 12 edges and 8 vertices. | A cuboid and a cube both have 6 faces, 12 edges and 8 vertices; only the shape of the faces differs. |
| 3 | 3 faces (2 flat circular faces and 1 curved face), 2 edges and 0 vertices. | The rims of the two circles are the edges; a rim has no sharp corner, so there are no vertices. |
| 4 | 6 vertices: 3 on each of the two triangular ends. | Check with Euler: vertices = edges – faces + 2 = 9 – 5 + 2 = 6. |
| 5 | 5 faces (1 square base plus 4 triangles), 8 edges and 5 vertices. | A pyramid always has an apex, so a square pyramid has the four base corners plus the apex. |
| 6 | 6 x 3 – 2 x 2 = 14 faces. | Each join hides 2 faces, so two joins hide 4 faces: 18 – 4 = 14. |
| 7 | 6 + 2 = 8 faces. | One straight cut adds 2 new flat faces, so the total number of faces rises by 2. |
| 8 | 18 / 3 = 6, so it is a hexagonal prism with 8 faces. | A prism has three times as many edges as base sides, and 2 more faces than base sides. |
| 9 | 2 faces is correct, but there is 1 edge (the rim of the base) and 1 vertex (the apex). | Every pyramid and cone has one apex, so the vertex count cannot be 0. |
| 10 | A sphere has only 1 curved face and no flat face, no edge and no vertex, so it rolls in any direction. | Standing still needs a flat face, and a sphere has none at all, so it only rolls. |
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.
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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.