numbers

NUMBERS.

classificatios of numbers:

natural numbers = N = (1,2,3,4,5...)
these are counting numbers. these are infinite.

whole number = W = (0,1,2,3,4,5...)
these are obtained on adding 0 to the natural numbers.

odd numbers = 1,3,5,7,9........
these are not multiples of 2. they can be represented in the form ( 2n-1 ). where n = a natural number.

even numbers = 2,4,6,8,10.....
these are multiples of 2. they can be represented in the form ( 2n ). where n=a natural number.

prime number = 1,3,5,7,11,....
a prime number is divisible only by one and itself, and not by others.

composite numbers = 2,4,6,8,9,10.......
a composite number has more than two factors, besites itself and unity. 1 is neither prime nor composite.

integers 1 to Z = (...-3,-2,-1,0,1,2,3....)
these consist of natural numbers, zero and negative of natural numbers
1,2,3.... are positive integers.
...-3,-2,-1......are negative integers.
0 is simply an integer - neither positive nor negative.


rational numbers = Q: 1/5, 2/3, 0, -5 etc...

these are of the form p/q, where q =/ 0.
every integer and all the fractions are rational numbers.
these maybe terminating or, non terminating repeating decimals.