01 - What is a Fraction? - Definition & Meaning - Part 1 - Numerator, Denominator & More.

View more at http://www.MathAndScience.com. In this lesson, you will learn what a fraction is, why they are important, and how to write fractions down to represent the amount of an object. We use fractions to describe the amount of an object we have when we have less than 1 whole object. The numerator of the fraction describes how many pieces we have and the denominator of the fraction determines how many pieces we cut the object into. For example, in the fractions 1/2 (one half), the numerator is 1 and the denominator is 2. This means that we have 1 out of 2 pieces of the object. We cut the item into two pieces, but we actually only have one piece. We use fractions in all of math, science, engineering, physics, chemistry, and more. Fractions are one of the most important concepts to learn in all of math.