Types of Numbers

A Natural number is a positive whole number, ie 0,1,2,3,4,5 etc.

An Integer number is a positive or negative whole number, i.e. -4,-3,-2,-1, 0, 1, 2, 3, 4 etc.

A Rational number is a number which can be expressed as a fraction, e.g.

An Irrational number is one which cannot be expressed as a fraction. It must be an infinite non-recurring decimal. Examples include - . (Note that is not irrational, because it is recurring - it is rational).