Class 9 Maths Chapter 1 NUMBER SYSTEM Introduction Part 1| Explained by IMRAN Sir#maths #class9 #ch1
Class 9 Maths Chapter 1, "Number System," is a fundamental chapter that introduces students to various types of numbers and their properties. Here's an overview of what you'll learn in this chapter: Types of Numbers *Natural Numbers*: These are counting numbers starting from 1, denoted by N (1, 2, 3, ...). *Whole Numbers*: These include natural numbers and zero, denoted by W (0, 1, 2, 3, ...). *Integers*: This set includes whole numbers and their negatives (...,-3, -2, -1, 0, 1, 2, 3, ...). *Rational Numbers*: These are numbers that can be expressed as a fraction of two integers, like 1/2 or 3/4. *Irrational Numbers*: These numbers cannot be expressed as simple fractions, examples include √2 and π. Key Concepts *Real Numbers*: The set of all rational and irrational numbers. *Decimal Expansion*: Rational numbers have either terminating or non-terminating recurring decimal expansions, while irrational numbers have non-terminating non-recurring decimal expansions. *Operations on Real Numbers*: You'll learn about the properties of real numbers, such as commutative, associative, and distributive laws, and how to perform operations like addition, subtraction, multiplication, and division.¹ ² ³ Important Topics *Representing Irrational Numbers on the Number Line*: You'll learn how to represent irrational numbers like √2 and √5 on the number line using Pythagoras' theorem. *Simplifying Expressions*: You'll practice simplifying expressions involving rational and irrational numbers. *Rationalizing the Denominator*: You'll learn how to rationalize the denominator of fractions with irrational numbers.⁴ Exercises and Activities Exercise 1.1: You'll become familiar with rational and irrational numbers, and learn how to represent numbers in the form of p/q. Exercise 1.2: You'll practice representing real numbers on the number line and expressing real numbers in decimal form. *Classroom Activities*: You'll engage in activities like constructing the "square root spiral" to visualize the representation of real numbers.
