Natural numbers or counting numbers are the number that is simply used for calculate the object or thinks.

Natural number is always starts with 1 and goes to infinity. The difference between the two successive natural numbers is always equal to 1.

The set of natural number is {1,2,3,4...} .

Integer is rational number means there should not be any fraction and in an integer after the decimal all numbers are zero.

Integer numbers lie in the range (−∞,+∞) .

So all integers are natural number, but all natural numbers is not an integer.

Thus, the set of natural number is {1,2,3,4,...} and all negative and zero are integers but not a natural number.

A rational number is a type of number which can be written in a form of fraction ab .

Where,

• a and b are an integer except zero in the denominator.

All rational numbers can be written in the form of terminating decimals, repeating decimals and an integer number.

Example:

2.5 is a rational number which is not an integer. 2.5 can be written in the form of fraction 52 .

Thus, the set of natural number is {12,−37,461,0.17,0.6} and 2.5 is a rational number not an integer.

A irrational number is a type of number which can be written in the ratio of an integers.

All irrational numbers cannot be written in the form of terminating decimals, repeating decimals and an integer number.

Example:

3 is an irrational number and its value is 1.73205080756 and so on.

An irrational number cannot be written in repeating decimals.

Thus, The set of natural number is {3,10,104,π2} and an example of irrational number is 3 .

A real number includes all the number such as rational number, irrational number, integer and all those numbers which can be expressed in the number line.

Example:

1 is an integer number.

45 is a rational number.

3 is an irrational number.

−4 is an integer number.

Thus, the set of real number is {1,45,3,104,π2,−4} .