Types of Numbers: Part-2
Integers: It is combination of both positive and negative numbers lying on the number line including zero. Remember zero is an integer. The integers are the natural numbers, their negatives, and the number zero like …,-3,-2,-1,0,1,2,3,… and they go on forever in both directions of the number line.
Rational numbers: Rational numbers are those, which can be written in the form of a ratio of x/ y, where the denominator y is non-zero.
Irrational numbers: Numbers, which are non-terminating and non- recurring (non-repeating) decimals are said to be irrational or we can say irrational numbers are those, which are not rational, that is those numbers that cannot be written in the form of a ratio x/y. For example = 1.414213….. , √3 =1.732050…..
Fractions: Fractions are those numbers, which are in the form of p/q where q is non-zero. For example 4/5, 5/6, 6/7 etc.
Real Numbers: Any number which can be plotted on the number line is a real number .The number can be positive or negative in nature. For example it may be like as 3, 4, 5, 6, -6, -5, -4, -3, -2…..
Prime Numbers and Composite numbers
In the list of natural numbers, there are two types of natural numbers.
One type is called the PRIME numbers and the other is called the COMPOSITE numbers.
(1 is not included in this list i.e.1 is neither prime nor composite)
Prime numbers: The numbers, which have exactly two factors, 1 and the number itself, are called prime numbers.
For example 2, 3, 5, 7, 11, 13, 31, 43,………………or we can say that the numbers, which are not divisible, by any number except one and itself, are called prime numbers. There are 25 prime numbers between 1 and 100.
Composite number: The composite numbers are those numbers which can be written as the product of prime numbers in a unique way.
Or we can say that the number which is the product of two or more than two distinct or same prime numbers is said to be a composite number.
Example 4, 6, 8,…
Note that composite number always has more than two factors and prime number cannot be a composite number.
Rounding numbers:When the number is approximated to the nearest possible integral value to maintain the accuracy of the data then the number is called rounded.