Maths Chapter 01: Rational Numbers

In Mathematics, we frequently come across simple equations to be solved. For example, the equation x + 2 = 13 is solved when x = 11, because this value of x satisfies the given equation.

The solution 11 is a natural number. On the other hand, for the equation x + 5 = 5, the solution gives the whole number 0 (zero). If we consider only natural numbers, equation cannot be solved. To solve such equations, we added the number zero to the collection of natural numbers and obtained the whole numbers.

Rational numbers are closed under the operations of addition, subtraction and multiplication. The operations addition and multiplication are:

• commutative for rational numbers
• associative for rational numbers

The rational number 0 is the additive identity for rational numbers. The rational number 1 is the multiplicative identity for rational numbers.

Between any two given rational numbers there are countless rational numbers. The idea of mean helps us to find rational numbers between two rational numbers.