“We use numbers to count”


“A number is a mathematical entity used in counting”


Just two of the possible ways to describe numbers, but of course numbers are far more than this. Numbers can be classified into many different subheadings. 


We have:



Natural numbers, real numbers rational numbers, irrational numbers, integers, fractions, even and odd numbers and prime numbers. This list could go on but for the benefit of this particular part of the book I don't want to make it too complicated. The first thing that we should do is briefly define each of the expressions that has just been listed above. I will start with (because I'm not going to do this in any particular order) "Real Numbers".