Solved Exercises on Cubes and Cylinders in Grade 1

Master 3D shapes: cubes and cylinders through these 5 detailed exercises with visual representations and comparison activities.

Solution: Exercises 1 to 3
1 Identifying Cubes
Exercise 1
Which object looks like a cube?
📦 (Box) vs 🥤 (Cup) vs ⚽ (Ball)
Definition:

Cube: A 3D shape with 6 square faces that are all the same size.

Method:
  1. Count the faces: 6 total
  2. Check if all faces are square
  3. Verify all faces are the same size
  4. Confirm all edges are straight
Features
6 square faces
Real-world
Dice, sugar cube, toy block
Step 1: Examine the box

Look at the front: it's a square 📦

Step 2: Count the faces

Front, back, left, right, top, bottom = 6 faces

Step 3: Check if all faces are squares

Yes, every face is a square of the same size

Box → Cube!
Final answer:

The box looks like a cube!

Applied rules:

• Face count: Exactly 6 faces

• Square faces: All 6 faces are squares

• Equal size: All faces are the same size

📦 ← This is a cube!
2 Identifying Cylinders
Exercise 2
Which object is shaped like a cylinder?
🥤 (Cup) vs 📦 (Box) vs ⚽ (Ball)
Definition:

Cylinder: A 3D shape with two circular bases connected by a curved surface.

Features
2 circular bases
Real-world
Can, cup, tube
Curved sides
Curved surface connects bases
Step 1: Look at the cup

It has a circular top and bottom: 🥤

Step 2: Count the bases

There are 2 circular flat surfaces

Step 3: Check the sides

The sides are curved and connect the two bases

Cup → Cylinder!
Final answer:

The cup is shaped like a cylinder!

Applied rules:

• Base pairing: Two identical circular bases

• Parallel bases: Bases are parallel to each other

• Curved connection: Curved surface connects the bases

🥤 ← This is a cylinder!
3 Comparing Cubes and Cylinders
Exercise 3
How are cubes and cylinders different?
📦 vs 🥤
Definition:

Comparison: Cubes have flat faces only, cylinders have curved surfaces.

Cube
6 flat faces
Cylinder
2 flat, 1 curved
Rolling
Cylinder rolls
Step 1: Look at the cube

All 6 faces are flat and square: 📦

Step 2: Look at the cylinder

Has curved sides between flat circular ends: 🥤

Step 3: Compare rolling ability

Cylinder rolls, cube slides

Step 4: Count flat surfaces

Cube: 6 flat surfaces, Cylinder: 2 flat surfaces

Cubes vs Cylinders: Different!
Final answer:

Cubes have 6 flat square faces, cylinders have 2 flat circular faces and 1 curved surface!

Applied rules:

• Surface types: Cubes = all flat, Cylinders = flat + curved

• Rolling behavior: Cylinders roll, cubes slide

• Face shapes: Cubes = square faces, Cylinders = circular faces

📦 ≠ 🥤
Rules and methods, laws,...
Cube: 6 faces, 12 edges, 8 vertices
3D Shape Properties
Cube
6 faces, 12 edges
All square faces
Cylinder
3 surfaces, 2 edges
2 circular bases
Comparison
Flat vs Curved
Different behaviors
Key definitions:

3D Shape: A solid figure that has length, width, and height

Face: A flat surface of a 3D shape

Edge: Where two faces meet

Vertex: A corner where edges meet

Surface: Any part of the outside of a 3D shape

Complete methodology:
  1. Observe: Look at the shape carefully
  2. Count faces: How many flat surfaces?
  3. Check shapes: Are faces square, circular, or curved?
  4. Test properties: Does it roll? Slide? Stack?
  5. Match to definition: Compare to known shapes
Tip 1: Count the faces to identify cubes (6 faces).
Tip 2: Look for circular bases to identify cylinders.
Tip 3: Test if it rolls (cylinders roll, cubes don't).
Tip 4: Practice with everyday objects like boxes and cans.
Common examples: Cubes (dice, building blocks), Cylinders (cans, cups, tubes).
Key insight: Cubes stack perfectly, cylinders can roll.
Properties to know by heart:

• Cube: 6 square faces, 12 edges, 8 vertices, all flat surfaces

• Cylinder: 2 circular bases, 1 curved surface, 2 edges, can roll

• Both take up space and have volume

• Cubes have sharp corners, cylinders have smooth curves

Exercise with Visualization: 3D Shape Comparison
Exercise 6: 3D Shape Properties Table
Compare the properties of cubes and cylinders:
Cube: 6 square faces
Cylinder: 2 circular bases, 1 curved surface
Property Cube Cylinder Examples
Faces 6 flat 2 flat, 1 curved Dice, box
Edges 12 2 Cup, can
Vertices 8 0 Toy block
Rolls? No Yes Tissue tube

Analysis: The table shows how cubes and cylinders have very different properties despite both being 3D shapes.

  • Cubes have more flat surfaces and sharp edges
  • Cylinders have curved surfaces and fewer edges
  • Rolling behavior is a key differentiator

Questions & Answers

Question: Why doesn't a cube roll like a cylinder? They're both 3D shapes!

Answer: Great question! The difference is in their surfaces:

  • Cube: Has 6 flat square surfaces, so when you push it, it just slides along those flat surfaces
  • Cylinder: Has curved surfaces on the sides, so when you push it, the curve allows it to roll smoothly

Think of it like this: If you try to roll a book (like a cube), it just slides. But if you try to roll a can (like a cylinder), it spins around because of its curved sides!

The curved surface of the cylinder acts like a wheel, while the flat surfaces of the cube prevent rolling.

Question: My child is mixing up cubes with rectangular prisms. How are they different?

Answer: That's a common confusion! Here's how they differ:

  • Cube: All 6 faces are squares of the same size (equal length, width, height)
  • Rectangular Prism: Faces are rectangles (length, width, height can be different)

Think of a cube as a "perfect" box where all sides are equal, like a dice. A rectangular prism is like a regular box where the sides can be different sizes, like a shoebox.

For grade 1, focus on cubes having all square faces of equal size, which makes them look very symmetrical.

Both have 6 faces, 12 edges, and 8 vertices, but cube faces are all squares while rectangular prism faces are rectangles.

Question: Can a cylinder stack on top of another cylinder like cubes do?

Answer: Yes, cylinders CAN stack on top of each other, but it depends on how you place them! Here's what happens:

  • If you place them with flat circular ends touching (top to bottom), they stack nicely like cubes
  • If you place them on their curved sides, they won't stack - they'll roll away

Cylinders stack best when you put the flat circular bases on top of each other, just like putting one cup inside another!

This is different from cubes, which can stack in any orientation because all their faces are flat and square.

So yes, cylinders can stack, but they need to be positioned with flat surfaces touching!