Rational numbers are numbers that can be expressed as a ratio of two integers.  They can be in fraction, decimal or whole number form.
 

Irrational numbers are numbers that cannot be expressed as a ratio of two integers. 

Go to the lesson on number subsets for further review.

Let's take a look at "pi" (π) for example.  Pi has many different forms and approximations. 

The three approximations of pi are rational numbers.

The actual number pi is an irrational number.

Non-perfect square roots are also irrational...

Examples are:, , and

   Let's do some practice problems!