Primary 4 Nets Study Guide
Primary 4 nets in five short steps: what a net is, then naming solids, drawing on the isometric grid, nets of a cube, which nets fold, and nets of prisms and pyramids, with something to try at each step and worked examples to finish.
Start here
What is a net of a solid?
A net is a solid opened out flat.
Cut along some edges of a box and open it out. The flat shape you get is a net: every face of the solid, joined edge to edge. Fold it back along the same edges and the solid comes back.
Everything in this chapter is about moving between the solid and the flat page:
- name a solid from its faces, and count its faces, edges and vertices in runs;
- draw a cube or cuboid on the isometric grid, with hidden edges dashed;
- tell whether six squares fold into a cube, and which faces end up opposite;
- name the solid that a net of a prism or pyramid folds into.
Step 1
Naming solids: faces, edges and vertices
Name it from its faces, then count in runs. A prism has the same face at both ends with rectangles between them. A pyramid has one base, and its other faces are triangles that meet at a point. Count edges in runs you can see, and count the hidden ones too.
Drag the solid to turn it
A pyramid has a square base. How many edges does it have?
Step 2
Drawing a cuboid on the isometric grid
Start at the lowest vertex and count steps, not dots. Three edges leave the lowest vertex along the grid's three directions. Every other edge is parallel to one of them. The three edges that meet at the back bottom corner are hidden, so they are dashed.
Tap the dots to draw
A cuboid is drawn on the isometric grid, seen from its lowest vertex. How many of its edges are drawn with dashes?
Step 3
Nets of a cube
Opposite is about the folded cube, not the flat paper. A net of a cube is six squares joined edge to edge. Once folded, each face touches four others along its edges and has exactly one opposite face. In a straight row, faces with one square between them are opposite.
Tap a face, then fold
A cube is folded from a net. How many faces of the cube touch face A along an edge?
Step 4
Which nets fold into a cube?
Six squares is not enough: each one needs its own place. Follow the folds from one square. If two squares land on the same face of the cube, another face is left open, and the shape is not a net of a cube.
Pick a shape, then predict
Five squares are joined in a straight row, and a sixth square is joined above the first one. Can it fold into a cube?
Step 5
Nets of prisms and pyramids
Count the shapes first, then follow the folds. Two matching triangles with rectangles between them make a triangular prism. One base with a triangle on every side makes a pyramid. The face a solid is named after is shaded blue.
Pick a net, then fold it
A net folds into a pyramid with a square base. How many triangles are in the net?
Primary 4 nets questions, worked step by stepTry each question first. Then show a hint, or the working one line at a time.
A solid has 5 faces. Two of them are triangles of the same shape and size, at opposite ends. The other 3 faces are rectangles.
(a) Name the solid.
(b) How many edges and how many vertices does it have?
- The same triangle is at both ends, with rectangles between them, so it is a triangular prism.
- Edges round the front triangle = 3. Edges round the back triangle = 3.
- Edges joining a front corner to the corner behind it = 3. Number of edges = 3 + 3 + 3 = 9.
- Vertices at the front = 3, at the back = 3. Number of vertices = 3 + 3 = 6.
The net of a solid is made of 1 square and 4 identical triangles. Each triangle is joined to one side of the square.
(a) Name the solid.
(b) How many vertices does the solid have?
- The square stays flat as the base, and each triangle folds up from one side of it.
- The tips of the 4 triangles meet at one point at the top, so the solid is a pyramid with a square base.
- Vertices round the base = 4. Vertex at the point on top = 1.
- Number of vertices = 4 + 1 = 5.
A cuboid is made of 24 unit cubes. Its base has a length of 4 units and a breadth of 3 units.
(a) How many units high is the cuboid?
(b) Draw the cuboid on the isometric grid, with its hidden edges dashed.
- Cubes in one layer on the base = 4 × 3 = 12.
- Number of layers = 24 ÷ 12 = 2, so the cuboid is 2 units high.
- From the lowest vertex, draw 3 edges: 4 steps up the slant to the right, 3 steps up the slant to the left, and 2 steps straight up.
- Draw the 6 edges parallel to these. Then dash the 3 edges that meet at the back bottom corner.
The net below is folded to make a cube.
(a) Which face is opposite face A?
(b) Which face is opposite face E?
- A, B, C and D are in a straight row. Folded, they wrap round to make the 4 sides of the cube.
- In a straight row, faces with one square between them are opposite. B is between A and C, so C is opposite A.
- E folds over from B to make the top, and F folds under from C to make the bottom.
- The top and the bottom are opposite, so F is opposite E, even though they are not in the same row.
A prism has 15 edges. How many faces does it have?
- The 3 runs have the same number of edges, so each run has 15 ÷ 3 = 5 edges.
- So each end face has 5 sides.
- Between the two ends there is one rectangle for each side of an end face: 5 rectangles.
- Number of faces = 2 ends + 5 rectangles = 2 + 5 = 7.
Step 6
Check yourself
Five quick questions from across the chapter. Answers are not saved; they show where to practise next.
1. How many vertices does a cuboid have?
2. Which solid has 1 flat face and 1 curved surface?
3. On the isometric grid, an edge passes through 5 dots, counting the dots at both ends. How many units long is the edge?
4. A net is made of 2 identical triangles and 3 rectangles. Which solid does it fold into?
5. Squares P, Q and R are in a straight row in a net of a cube, with Q in the middle. Which face is opposite P when the net is folded?
How to use this guide. Sit with your child for the folding steps. Before they press Fold, ask "Which face will this one land on?" A guess said aloud, then checked, is how the picture in their head gets built. Each step takes two or three minutes; the whole guide about fifteen.
A real box helps too. Open a small cereal box along its edges, lay it flat, and you have a net of a cuboid to fold back up together. Then try the worked examples: let your child try first, and reveal the working one line at a time.
More study guides
P4 Nets lessons and practice
3 lesson videos and 32 questions across three subtopics, from Basic to Challenge, each with a worked solution.
Watch and practise →