INTRODUCTION

A huge uncut pizza is an example of a WHOLE.

When you share the pizza fairly with your friends you cut it into EQUAL PARTS.

The EQUAL PARTS that make up the WHOLE pizza is an example of a FRACTION.
If you had a WHOLE pizza and cut it into four pieces you would have four fourths or 4/4.
If you and two friends had a slice, that would be three slices, you and your friends would have eaten three of the fourths or 3/4.

The top number of a fraction is called the numerator; it is the number that we talk about. For example we talked about you and your friends eating 3 slices out of the four, the three slices is the numerator.

The bottom number of a fraction is called the denominator; it is the number of equal parts that make up the whole. For example the whole pizza was cut into four slices, the four slices is the denominator.