NCERT Class 8 Mathematics Ganita Prakash Part-I: Chapter 2 — Power Play
This chapter, 'Power Play,' from NCERT Class 8 Mathematics Ganita Prakash Part-I, introduces the concept of exponential growth through a relatable scenario of folding a sheet of paper. It challenges students to consider how many times a paper can be folded and explores the astonishing thickness it would reach. Starting with a paper thickness of 0.001 cm, the chapter demonstrates how the thickness doubles with each fold. It presents a table showing the thickness after various folds, illustrating rapid increases from centimeters to meters and kilometers. The chapter highlights that after 30 folds, the paper's thickness would be approximately 10.7 km, comparable to the altitude at which planes fly, and after 46 folds, it could reach the Moon. This exploration aims to help students grasp the immense power of repeated multiplication and exponential growth in mathematics, crucial for understanding various scientific and real-world phenomena.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 8 |
| Subject | Mathematics |
| Book | Ganita Prakash Part-I |
| Chapter | Chapter 2 — Power Play |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 3 minutes |
| Word count | 437 |
Learning outcomes
- Understand the concept of exponential growth through practical examples.
- Recognize how repeated multiplication leads to rapid increases in quantity.
- Calculate and estimate the thickness of a paper after multiple folds.
- Relate mathematical concepts to real-world phenomena like the height of buildings and distances.
- Develop an intuitive understanding of powers and exponents.
Vocabulary
| Word | Meaning |
|---|---|
| Fold | To bend something over on itself so that one part covers another. |
| Thickness | The measurement of how thick something is. |
| Impossible Venture | An undertaking or attempt that seems impossible to achieve. |
| Approximately | Close to the actual, but not completely accurate or exact. |
| Exponential Growth | Growth that becomes more and more rapid at a fixed rate. |
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Practice questions
- If a sheet of paper is 0.1 mm thick, what would be its thickness after 5 folds? Answer: After 1 fold: 0.2 mm, 2 folds: 0.4 mm, 3 folds: 0.8 mm, 4 folds: 1.6 mm, 5 folds: 3.2 mm.
- The chapter states that after 17 folds, the thickness is approximately 131 cm. How many feet is this, approximately? (1 foot = 30.48 cm) Answer: Approximately 131 cm / 30.48 cm/foot ≈ 4.3 feet.
- Why is it impossible to fold a sheet of paper more than 7 times in reality? Answer: The paper becomes too thick and small to fold further due to the exponential increase in thickness with each fold.
- What is the approximate thickness of the paper after 20 folds, as mentioned in the chapter? Answer: Approximately 10.4 meters.
Frequently asked questions
What is the main concept introduced in the NCERT Class 8 Mathematics Chapter 2, 'Power Play'?
The chapter introduces the concept of exponential growth and how quantities can increase dramatically through repeated multiplication, using the example of folding a paper.
What is the initial thickness of the paper assumed in the chapter?
The initial thickness of the paper is assumed to be 0.001 cm.
How does the thickness of the paper change with each fold?
The thickness of the paper doubles after each fold.
What is the approximate thickness of the paper after 30 folds?
After 30 folds, the thickness of the paper is about 10.7 km.
What real-world comparisons are made to illustrate the thickness after many folds?
Comparisons are made to the height of the Burj Khalifa (830 m), the depth of the Mariana Trench (11 km), and the typical altitude at which planes fly (around 10.7 km).
What is the significance of the 'Impossible Venture' section?
It highlights the surprising and rapid increase in thickness when folding paper repeatedly, demonstrating the power of exponential growth.
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NCERT Class 8 Mathematics — Ganita Prakash Part-I — Chapter 2 — Power Play. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.