NCERT Class 3 Maths (Maths Mela) · Chapter 2
Toy Joy
3D shapes (cube, cuboid, cylinder, cone, sphere), their faces, edges and corners, and building toys with shapes.
📌 What you’ll learn in this chapter
- Names of 3D shapes: cube, cuboid, cylinder, cone, sphere
- Faces (flat or curved), edges, and corners
- Finding shapes in toys and around us
- Building models with shapes and describing them
🧸 Let’s Begin: The Toy Shop
Ravi visits a toy shop. He sees a ball (sphere), a drum (cylinder), a birthday cap (cone), a dice (cube), and a toy truck made of boxes (cuboids)!
All toys are made from a few simple shapes.
📦 Part 1: Meet the Shapes
| Shape | Looks like | Faces | Can it roll? |
|---|---|---|---|
| Cube | Dice, Rubik’s cube | 6 flat, all squares | No |
| Cuboid | Brick, matchbox, book | 6 flat, rectangles | No |
| Cylinder | Glass, pipe, candle | 2 flat + 1 curved | Yes, on its side |
| Cone | Ice-cream cone, cap | 1 flat + 1 curved | Yes, in a circle |
| Sphere | Ball, laddoo, orange | 1 curved | Yes, any way |
💡 Words to know
Face = the surface you can touch · Edge = where two faces meet · Corner = where edges meet
A cube is a special cuboid with all faces the same size.
A cube is a special cuboid with all faces the same size.
🎲 Part 2: Dice Fun
On a die, opposite faces add up to 7: 1 and 6, 2 and 5, 3 and 4.
🏗️ Part 3: Building with Shapes
A toy house can be a cuboid with a cone or triangular block on top. A rocket can be a cylinder with a cone on top. Use words like on, under, between, and beside to describe your model.
⚠️ Common mistake
Calling a cube a “square”. A square is flat (you draw it on paper). A cube is solid (you can hold it)!
✏️ Practice Time
Try these on your own first, then check your answer below each question.
Q1. Name the shape: a football, a matchbox, a candle.
✅ AnswerSphere, cuboid, cylinder
Q2. Which shape has no edges and no corners?
✅ AnswerSphere
Q3. How many faces does a cube have?
✅ Answer6
Q4. What number is opposite 4 on a die?
✅ Answer3 (4 + 3 = 7)
📘 NCERT Textbook Activity Help
Hints and answers for the activities in the textbook, page by page. Try each one yourself before looking at the answer!
Page 9 · Jaya’s rocketShapes used
✅ AnswerLook at the rocket from top to bottom: a pink cone on the top, then 2 cubes (purple and blue), then a big orange cylinder, with cuboids around the bottom (yellow, green, red, blue). Count the cuboids in your book. The cubes are on top of the orange cylinder, and the purple cube is under the pink cone.
Page 10 · Devika’s engine and toysCount the parts
✅ AnswerThe engine has 1 red cylinder (the body), 1 yellow cone (the chimney top), grey cuboids (the base), and a blue cube (the cabin). Count each colour in your book.
Toys: mouse → cone + cylinder · lollipop → sphere + cylinder (stick) · cat → cylinders and a sphere head · block toy → cubes and cuboids
Pages 11–12 · Shapes in the classroomToys: mouse → cone + cylinder · lollipop → sphere + cylinder (stick) · cat → cylinders and a sphere head · block toy → cubes and cuboids
Find and name
✅ AnswerExamples: cylinder → dustbin, bottle · sphere → globe, ball · cube → dice · cuboid → duster, box, cupboard · cone → funnel, birthday cap. In most classrooms, the cuboid is the shape you find the most.
Q3: No edges → sphere · Only flat faces → cube, cuboid · Only a curved face → sphere · Straight and curved edges → a cylinder has curved edges, and a cone has one curved edge · Both flat and curved faces → cylinder, cone
Pages 13–15 · More questionsQ3: No edges → sphere · Only flat faces → cube, cuboid · Only a curved face → sphere · Straight and curved edges → a cylinder has curved edges, and a cone has one curved edge · Both flat and curved faces → cylinder, cone
Dice and models
✅ AnswerQ6: A cube and a cuboid both have 6 flat faces, 12 edges, and 8 corners. The cube’s faces are all equal squares, but the cuboid has rectangles.
Q7: Opposite 1 is 6, opposite 2 is 5, and opposite 3 is 4. The pattern is that opposite faces add up to 7.
Joining a cube and a cuboid makes a longer cuboid (if they match in size). 3 cubes can be joined in a straight line or in an L-shape.
Q11: Put 6 dice in 2 rows of 3 to make a cuboid, or stack 6 in a tower.
Q7: Opposite 1 is 6, opposite 2 is 5, and opposite 3 is 4. The pattern is that opposite faces add up to 7.
Joining a cube and a cuboid makes a longer cuboid (if they match in size). 3 cubes can be joined in a straight line or in an L-shape.
Q11: Put 6 dice in 2 rows of 3 to make a cuboid, or stack 6 in a tower.
👨👩👧 Tips for Parents
- Collect empty boxes, bottles, and cans, and build a toy together.
- Go on a shape hunt: “Find 3 cylinders in the kitchen!”
- Check that opposite faces of a die add up to 7.