NCERT Class 6 Mathematics Ganita Prakash: Chapter 5 — Prime Time
This chapter introduces the concepts of common multiples and common factors through an engaging 'Idli-Vada' game. Students learn to identify multiples of given numbers and understand what happens when numbers are multiples of two different numbers simultaneously. The game involves saying 'idli' for multiples of 3, 'vada' for multiples of 5, and 'idli-vada' for numbers that are multiples of both 3 and 5. The chapter poses questions to help students calculate the frequency of these terms and explore patterns. It also encourages drawing figures to visualize common multiples up to a certain number, reinforcing the understanding of multiples and common multiples in a fun, interactive way, crucial for building a strong foundation in number theory for CBSE Class 6 Mathematics.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 6 |
| Subject | Mathematics |
| Book | Ganita Prakash |
| Chapter | Chapter 5 — Prime Time |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 3 minutes |
| Word count | 435 |
Learning outcomes
- Understand the concept of multiples of a number.
- Identify common multiples of two or more numbers.
- Apply the concept of multiples in a game-based learning scenario.
- Solve problems related to common multiples up to a given number.
- Differentiate between multiples of individual numbers and common multiples.
Vocabulary
| Word | Meaning |
|---|---|
| Multiples | Numbers obtained by multiplying a given number by any integer. |
| Common Multiples | Numbers that are multiples of two or more given numbers. |
| Idli | A term used in the game for multiples of 3. |
| Vada | A term used in the game for multiples of 5. |
| Idli-Vada | A term used in the game for numbers that are multiples of both 3 and 5. |
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Practice questions
- What are the first five multiples of 4? Answer: 4, 8, 12, 16, 20
- List the common multiples of 2 and 3 up to 20. Answer: 6, 12, 18
- In the 'Idli-Vada' game, for which numbers should players say 'idli'? Answer: Multiples of 3 (e.g., 3, 6, 9...).
- What is the first number for which players say 'idli-vada' in the game? Answer: 15
Frequently asked questions
What is the 'Idli-Vada' game?
It's a number game where players say 'idli' for multiples of 3, 'vada' for multiples of 5, and 'idli-vada' for common multiples of 3 and 5.
What are common multiples?
Common multiples are numbers that are multiples of two or more given numbers.
What is the first common multiple of 3 and 5?
The first common multiple of 3 and 5 is 15.
How does the game help in learning mathematics?
It makes learning about multiples and common multiples interactive and fun, reinforcing the concepts through practical application.
What does it mean to say 'idli' in the game?
Saying 'idli' means the number is a multiple of 3.
What does it mean to say 'vada' in the game?
Saying 'vada' means the number is a multiple of 5.
Related resources
Important topics
Topics covered
NCERT Class 6 Mathematics — Ganita Prakash — Chapter 5 — Prime Time. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.