Number System Class 9

Number System

Number System is the first topic in class IX NCERT Maths book. In this topic, you will learn about Irrational Numbers the decimal representation of Rational Numbers. Square root spiral and Law of Exponents for Real Numbers. Here you will get a quick revision of the topic. Before you start solving problems of the topic, first read it. It will help you in problem-solving.

CBSE Syllabus

Unit 1:  REAL NUMBERS 

1. Review of representation of natural numbers, integers, and rational numbers on the number line. Rational numbers as recurring/ terminating decimals. Operations on real numbers. 

2. Examples of non-recurring/non-terminating decimals. Existence of non-rational numbers (irrational numbers) such as $\sqrt{2},\sqrt{3}$, and their representation on the number line. Explaining that every real number is represented by a unique point on the number line and conversely, viz. every point on the number line represents a unique real number. 

3. Definition of nth root of a real number. 

4. Rationalization (with precise meaning) of real numbers of the type $\frac{1}{a+b\sqrt{x}}and \frac{1}{\sqrt{x}+\sqrt{y}}$ and (and their combinations) where x and y are natural number and a and b are integers. 

5. Recall of laws of exponents with integral powers. Rational exponents with positive real bases (to be done by particular cases, allowing learner to arrive at the general laws.) 

 Quick Revision