Arithmetic/Types of Numbers
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We can classify numbers into several different kinds.
Contents |
[edit] Natural number
The natural numbers are those that children first learn about, the positive whole numbers used for counting, i.e. 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38.....
[edit] Whole number
A whole number is a number that is either a natural number or zero.
[edit] Integer
An integer expands the set of whole numbers by including numbers less than zero (or negative numbers). Thus integers are the numbers ...-2, -1, 0, 1, 2...
[edit] Negative Numbers
Any value less than 0. This is represented by a - sign on the left side of the value.
Examples:
...,-10,-9,-8,-7,-6,-5,-4,-3,-2,-1
-1/2
-0.000000423423234
-π
[edit] Rational number
A rational number is a number which can be written in the form of one integer divided by another or a/b where b ≠ 0. For technical purposes, a and b must be relatively prime (only common factor between a and b is 1). Note that all integers are rational since they can all be expressed as the integer divided by one.
[edit] Irrational number
An irrational number is a number which is not a rational number. Examples of irrational numbers include 
and π.
[edit] Real number
Real numbers include all rational and irrational numbers. The real numbers form the continuous 'real line' of numbers.
[edit] Complex number
Complex numbers are of the following form: z = a + bi where: a and b are real numbers and i is the 'imaginary unit' 
.
