---
type: "Chapter"
knowledge_type: "chapter"
entity_type: "chapter"
id: "69be7f3cb44bd98134fb2892"
title: "NUMBER PLAY"
board: "CBSE"
curriculum: "CBSE"
class: "Class 7"
subject: "Mathematics"
book: "Ganita Prakash"
chapter: "NUMBER PLAY"
chapter_slug: "number-play"
canonical_url: "https://www.edzy.ai/cbse-class-7-mathematics-ganita-prakash-number-play"
markdown_url: "https://www.edzy.ai/okf/chapter/cbse-class-7-mathematics-ganita-prakash-number-play.md"
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source: "Edzy"
version: 1
last_updated: "2026-06-24"
---

# NUMBER PLAY
This chapter introduces students to interesting concepts related to numbers and their arrangements. It explores how different numbers can convey specific meanings when interpreted through various scenarios, such as height arrangements and the properties of odd and even numbers.

## Knowledge Snapshot

| Field | Details |
| :--- | :--- |
| Class | Class 7 |
| Subject | Mathematics |
| Book | Ganita Prakash |
| Chapter | NUMBER PLAY |
| Pages | 127-145 |

## Chapter Summary

### Short Summary
The chapter focuses on the meanings conveyed by numbers through different arrangements and explores concepts of parity in mathematical operations.

### Detailed Summary
The chapter elaborates on the significance of numbers as children arrange themselves based on height and the numbers they call out, which reflect the height of others in front of them. It subsequently introduces puzzles involving odd and even numbers, discussing how pairs of odd and even numbers yield specific sums, leading to the realization that odd numbers cannot sum to an even number when in a specified odd count of boxes. This concept is extended to explore the parity of expressions and the number of squares in grids, concluding with formulas for identifying odd and even numbers.

## Topic-Wise Explanation

### Numbers Tell us Things
This section presents a scenario where children count the number of taller individuals in front of them, demonstrating how numbers can provide information based on arrangements. Various configurations of stick figures are explored to reinforce this concept.

### Picking Parity
This topic introduces Kishor's puzzle of arranging cards to sum to 30, illustrating the impossibility of combining odd cards to achieve an even sum. It also discusses examples of odd and even number combinations.

### Small Squares in Grids
The section examines the parity of squares in different grid arrangements, emphasizing that one can predict the parity without direct calculation.

### Parity of Expressions
This section analyzes mathematical expressions for varying values of \(n\), showcasing how to derive odd and even outcomes through specific formulations and their properties.

## Core Ideas

| Idea | Explanation |
| :--- | :--- |
| Numbers convey information | Arrangements change the information numbers can convey based on rules. |
| Parity is important in arithmetic | Understanding whether numbers are odd or even affects their sum and product. |

## Key Concepts

| Concept | Meaning |
| :--- | :--- |
| Parity | The quality of being even or odd. |
| Expression | A combination of numbers and variables forming a mathematical statement. |

## Important Points for Revision

* Numbers can convey specific meanings based on their arrangement.
* Odd and even numbers follow distinct rules in addition and multiplication.
* The sum of two odd numbers is even, while the sum of any odd number of odd numbers is odd.
* The parity of the sum of grid squares can be determined by the grid dimensions.
* Various expressions can yield either odd or even results based on their components.

## Practice Questions

### Short Answer Questions
1. What does a child mean when they say the number '0'?
2. How can Kishor achieve a sum of 30 with number cards?
3. What is the parity of the expression \(3n + 4\) for \(n = 3\)?
4. Describe what happens when you add two odd numbers.
5. How many squares are in a 3 × 4 grid?

### Long Answer Questions
1. Explain the significance of arranging children by height and how it affects the numbers they call out.
2. Discuss the implications of odd and even number combinations in arithmetic operations demonstrated in this chapter.
3. Derive a formula for the nth odd number based on the expressions discussed.

## Source Attribution

| Field | Value |
| :--- | :--- |
| Source | Edzy |
| Reference Type | examSubjectBookChapter |
| Reference ID | 69be7f3cb44bd98134fb2892 |
| Canonical URL | https://www.edzy.ai/cbse-class-7-mathematics-ganita-prakash-number-play |
| Markdown URL | https://www.edzy.ai/okf/chapter/cbse-class-7-mathematics-ganita-prakash-number-play.md |