chapter 2 std 9

Rational numbers(BHINNKA SANGHAYA),Irrational numbers(ABINAKHA SANGHYAKAL)
Rational numbers (BHINNKA SANGHAYA) and Fractions(BHINNA SANGHYA)

Integers->....,-3,-2,-1,0,1,2,3,...
Positive integers-> 1,2,3,4,...
Negative integers-> -1,-2,-3,...
Whole numbers->0,1,2,3,4,...

Rational number=Integers+fractions(A number which can be expressed in the form of p/q,where p and q are integers and q#0).

Integers and fractions (positive or negative) are collectively
called rational numbers.
If we write a rational number to a decimal,then it may be either
1. terminating decimals
or
2.repeating decimals

Irrational numbers
irrational numbers are precisely those real numbers that cannot be represented as terminating or repeating decimals.
You could have pi/2, or sqr(2)/2, both of which are fractions that are NOT rational.
That means the square root of 2 cannot be written as a fraction where the numerator and denominator are integers.

Fractions
A fraction (from the Latin fractus, broken) is a number that can represent part of a whole
fraction