Get the official The World of Numbers chapter from the new Ganita Manjari textbook right here. This Class 9 Maths Book PDF Chapter 3 The World of Numbers is the exact NCERT file for the 2026-27 session. Read it to learn rational numbers, irrational numbers, and surds from the source before your Class 9 annual exam.
- Length: the official chapter PDF runs to 27 pages of text, number lines, and exercises.
- What it teaches: rational and irrational numbers, real numbers, decimals, and surds.
- New book: this is the 2026-27 Ganita Manjari book, so this topic is now Chapter 3.
This is the original NCERT chapter file, matched to the current 2026-27 syllabus, so every page, number line, and exercise number is exactly what your teacher uses in class.
What's in the Class 9 Maths The World of Numbers NCERT Book PDF?
The Class 9 Maths Book PDF Chapter 3 The World of Numbers is a 27-page chapter. It starts with the story of numbers, from counting to zero to negatives, then defines rational and irrational numbers. The file shows how real numbers fill the number line, sorts terminating and repeating decimals, and teaches surds, rationalising, and the laws of exponents. It ends with five exercise sets and an End-of-Chapter set.
Video Chapter Walkthrough
Source: Vedantu CBSE 10th on YouTube
The World of Numbers Section-by-Section Overview
The chapter builds the full number family in a clear order. The table below maps each section to what you will learn.
| Section | Topic | What you will learn |
|---|---|---|
| The Story of Numbers | Number families | How counting, zero, and negatives grew into the number families |
| Rational Numbers | Ratios on the line | What a rational number is and why they never run out |
| Irrational Numbers | Non-ratios | Why √2 is irrational and how to build irrational lengths |
| Real Numbers and Decimals | Complete number line | Terminating, repeating, and non-repeating decimals |
| Working with Real Numbers | Surds and exponents | Surd rules, rationalising a denominator, and laws of exponents |
Solved Examples and Exercises in The World of Numbers
The chapter gives in-text solved examples first, then exercise sets to practise. Read the solved examples before you try each set.
- Exercises 3.1 to 3.5: five sets covering rationals, decimals, surds, and exponents.
- End-of-Chapter Exercises: mixed problems that pull the whole chapter together.
- In-text solved examples: step-by-step models placed through the chapter text.
What Changed in the 2026-27 The World of Numbers Chapter
This chapter comes from the new Ganita Manjari book, which replaces the old 15-chapter NCERT Maths book. The new book is activity-based, so the number families are taught through history and number-line building rather than dry rules. In the old book, this content was titled Number Systems. The new title, The World of Numbers, and its Chapter 3 slot give a friendlier route into surds and real numbers.
How to Read the The World of Numbers Chapter
Read the Class 9 Maths Book PDF Chapter 3 The World of Numbers with a number line drawn on paper. Skim once to see the flow, then read slowly and place each new number on the line. Work through the solved examples, and only then try the exercises. This skim, then detail, then examples, then exercises order makes surds far less scary.
How will Collegedunia Help You with the The World of Numbers NCERT Book?
Collegedunia pairs the Class 9 Maths Book PDF Chapter 3 The World of Numbers with free study support, so surds and exponents stay simple.
- Free download: get the official chapter PDF in one click, with no sign-up.
- Matched resources: open the notes, formula sheet, and solutions for the same chapter.
- 2026-27 ready: every linked resource follows the new Ganita Manjari book.
- Exam focus: the support is framed for your Class 9 annual exam and the base for Class 10 number work.
More The World of Numbers Maths Class 9 Resources
Use the box below to open other study resources for the same chapter.
NCERT Book PDF for Class 9 Maths: All Chapters
Use the table below to open the NCERT Book PDF for any other chapter of the new Class 9 Maths book.
| Chapter | Resource |
|---|---|
| Chapter 1 | Coordinates NCERT Book PDF |
| Chapter 2 | Linear Polynomials NCERT Book PDF |
| Chapter 3 | The World of Numbers NCERT Book PDF |
| Chapter 4 | Algebraic Identities NCERT Book PDF |
| Chapter 5 | Circles NCERT Book PDF |
| Chapter 6 | Perimeter and Area NCERT Book PDF |
| Chapter 7 | Introduction to Probability NCERT Book PDF |
| Chapter 8 | Sequences and Progressions NCERT Book PDF |
The World of Numbers Class 9 Maths NCERT Book PDF FAQs
Ques. How many pages is the Class 9 Maths The World of Numbers NCERT Book PDF?
Ans. The official Chapter 3 The World of Numbers file runs to 27 pages. It holds the full text, number lines, five exercise sets, and the End-of-Chapter set.
Ques. Is The World of Numbers part of the new Ganita Manjari book?
Ans. Yes. It is Chapter 3 of the new Ganita Manjari book for the 2026-27 syllabus. In the old NCERT book, this content was called Number Systems.
Ques. Is this the official NCERT chapter PDF?
Ans. Yes. This is the original NCERT chapter file, not a copy, so the pages and exercise numbers match the book your school uses.
Ques. What exercises does Chapter 3 have?
Ans. The chapter has five exercise sets, 3.1 to 3.5, and one End-of-Chapter set, along with in-text solved examples.
Ques. Does this chapter cover surds and rationalising?
Ans. Yes. The chapter teaches surd rules, how to rationalise a denominator, and the laws of exponents for real numbers.
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