# Class 7 Mathematics Chapter 9 Rational Number Exercise 9.1

*A number that can be expressed in the form p/q, where p and q are integers and q is not equal to zero, is called a rational number.

* All integers and fractions are rational numbers.

* If the numerator and denominator of a rational number are multiplied or divided by a non-zero integer, we get a rational number which is said to be equivalent to the given rational number.

* Rational numbers are classified as positive and negative rational numbers.

*When the numerator and denominator, both, are positive integers, it is a positive rational number.

* When either the numerator or the denominator is a negative integer, it is a negative rational number.

* The number 0 is neither a positive nor a negative rational number.

* A rational number is said to be in the standard form if its denominator is a positive integer and the numerator and denominator have no common factor other than 1.