untitled

Natural Number
1 , 2 , 3 , 4 ......... etc. numbers are called natural number or positive whole numbers.
2 , 3 , 5 , 7 ......... etc. are prime numbers and 4 , 6 , 8 , 9 ,......... etc. are composite numbers.
Integers
All numbers (both positive and negative) with zero (0) are called integers i.e. .......
 3 , 2 , 1 , 0 , 1 , 2 , 3 ......... etc. are integers.
Fractional Number

If p,q are co-prime numbers ; qz 0 and qz 1 , numbers expressed in
q

p

form are

called fractional number.

Example :
3

5

2

3

2

1 

, , etc. are fractional numbers.

If pq, then it is a proper fraction and if p!q then it is an improper fraction :

Example , , , ,.........
4

1

3

2

3

1

2

1

etc. proper and , , , ,....

4

5

3

5

3

4

2

3

etc. improper fraction.

Rational Number

If p and q are integers and qz 0 , number expressed in the form
q

p

is called rational

number. For example : 1. 666 ...
3

5

5. 5 ,

2

11

3 ,

1

3

etc. are rational numbers.

Rational numbers can be expressed as the ratio of two integers. So, all integers and all
fractional numbers are rational numbers.
Irrational Number

Numbers which cannot be expressed in
q

p

form, where p,q are integers and qz 0 are

called Irrational Numbers. Square root of a number which is not perfect square, is an

irrational number. For example: 2 1. 414213 ....., 3 1. 732 ....., 1. 58113 ....
2

5

etc. are irrational numbers. Irrational number cannot be expressed as the ratio of two
integers.
Decimal Fractional Number
If rational and irrational numbers are expressed in decimal, they are known as decimal

fractional numbers. As for instance, 33333 ......., 3 1732 .........
3
25 ,^10
2
3 3 ˜ 0 ,^5 ˜ ˜ ˜ etc.
are decimal fractional numbers. After the decimal, if the number of digits are finite, it is
terminating decimals and if it is infinite it is known as non-terminating decimal number.
For example, 0.52, 3.4152 etc. are terminating decimals and
1 ˜ 333 ......., 2 ˜ 123512367 ...........etc. are non-terminating decimals. Again, if the digits