Lesson 6: Fractional Parts

New Concept

A fraction has a numerator (top number) showing parts represented and a denominator (bottom number) showing total equal parts in the whole.
To find a fractional part of a group, we can divide the group by the denominator.

What’s next

This is just the start of working with fractions. Next, you'll tackle worked examples finding fractional parts of shapes, groups, and money.

Property

A common fraction is written with two numbers and a fraction bar. The “bottom” number is the denominator, showing the number of equal parts in the whole. The “top” number, the numerator, shows the number of parts being represented.

Examples

A circle with one of six equal parts shaded is represented by the fraction $\frac{1}{6}$.

If four out of five friends in a group are wearing hats, that's $\frac{4}{5}$ of the group.

Property

To find a unit fraction (a fraction with a numerator of 1) of a number, divide that number by the denominator. For example, finding $\frac{1}{2}$ of 450 is the same as calculating $450 \div 2$.

Examples

• What number is $\frac{1}{2}$ of 540? We simply calculate $540 \div 2 = 270$.
• What number is $\frac{1}{4}$ of 1000? We calculate $1000 \div 4 = 250$.
• How much money is $\frac{1}{3}$ of 3.60 dollars? We calculate $3.60 \div 3 = 1.20$ dollars.

Explanation

What is $\frac{1}{5}$ of 100? This fraction is just a secret mission for division! The denominator (the bottom number) tells you what to divide by. Just take the big number (100) and divide it by the bottom of the fraction (5). Shazam! You get 20. It’s a ninja trick for splitting up numbers without breaking a sweat.