CBSE Class 8 Maths Notes for Chapter 1 Rational Numbers

 CHAPTER 1 RATIONAL NUMBERS
 
PROPERTIES OF RATIONAL NUMBERS

1. Closure property
2. Rational numbers follow closure property under addition, subtraction and multiplication
3. Rational numbers are, however, not closed under division.

2. Commutativity

• Rational numbers follow commutative property under addition, subtraction and multiplication.
• Rational numbers do not follow commutative property under division.

3. Associativity

• Addition and multiplication are associative for rational numbers.
• Subtraction and division are not associative for rational numbers

 
ZERO
Zero is the identity for addition of rational numbers.
 
ONE
One is the multiplicative identity for rational numbers.
 
ADDITIVE INVERSE
The additive inverse of a/b  is – a/b and vice versa.
MULTIPLICATIVE INVERSE
The multiplicative inverse is the reciprocal of the rational number i.e. the multiplicative inverse of a/b  is b/a.