A Number Isn’t Just a Number
There are six classifications for numbers and these classifications can overlap.
Natural numbers, also known as the counting numbers, begin at 1. Think of something you can count. Pencils, books, doggie biscuits….these are things that can be counted. You are probably thinking that you can have 0 of something. That is true, but you don’t begin counting something you actually have at 0.
Whole numbers include all the natural numbers and also 0. Within the classification of whole numbers, you have even numbers (2, 4, 6, 8..) and odd numbers (3, 5, 7, 9…)
Whole numbers are either prime or composite. This can be determined by factoring. Factors are numbers that another number can be wholly divided or divisible. Prime numbers only have two factors: 1 and the number itself e.g. 13’s only factors are 1 and 13. There are no other two whole numbers that can go evenly into 13. A composite number can have other numbers divide evenly into it e.g. the number 6 can be factored by 1, 2, 3, and 6.
Integers includes all of the above and it includes whole negative numbers too.
Rational numbers are where the rules can start to get tricky. Any number that can be written as a fraction is considered to be a rational number. Take note that this does not mean that it can only be written as a fraction. Fractions can be converted into decimals.
Irrational numbers cannot be made into fractions. You might be scratching your head. What number can’t be a fraction? Think square roots of prime numbers. Not sure what a square root is? No worries…square roots are covered a little later here. Also, irrational numbers are any decimals that are non-terminating or non-repeating. The best example of this is pi (Π). Pi is shortened to 3.14 for basic math problems, but actually goes beyond a trillion digits.
Real numbers encompass all the numbers, both rational and irrational. Simply, if it is number, of any kind, then it is considered a real number.
