We use fractions to solve many everyday problems. For example, in recipes, ingredients are often measured in fractions of a cup. If we wanted to know the total volume of the ingredients, we could use fraction addition.
Here are some tips for applying fractions to real world problems:
- When we describe equal parts out of a whole, we can write the situation as a fraction. For example, if a prize was split $6$6 ways, each recipient would get $\frac{1}{6}$16 of the total.
- The denominator is the total number of parts. In some cases, we can find it by adding together all of the parts. For example, if Mick picked $4$4 strawberries and Rachel picked $5$5, then Mick picked $\frac{4}{4+5}=\frac{4}{9}$44+5=49 of the strawberries.
- If we want to find a fraction of a quantity, we can multiply the fraction by the quantity. This works if the quantity is a fraction as well. For example, if we want to find $\frac{2}{3}$23 of $\frac{1}{10}$110 of a minute in seconds, we would find $\frac{2}{3}\times\frac{1}{10}\times60$23×110×60.
- Fractions are also a way to write division. If a piece of timber was divided into $5$5 parts, each part would be $\frac{1}{5}$15 of the original piece.
- Improper fractions and mixed numbers can be used to represent more than one whole. For example, if Francisco ran one lap around a track and then ran another third of the track, he has run $\frac{4}{3}$43 or $1\frac{1}{3}$113 laps.
Practice questions
Question 1
Carl has $\frac{3}{7}$37m of ribbon. After he uses some ribbon for a present, he has $\frac{1}{4}$14m left.
How much ribbon did he use on the present?
Question 2
At a party, Bill makes a drink by combining $5\frac{1}{3}$513L of water with $1\frac{1}{2}$112L of cordial.
What is the total amount of the drink as a mixed number?
Question 3
Jack is making bags for his friends. He has $3\frac{1}{2}$312m of fabric.
If each bag requires $\frac{2}{5}$25m of fabric, how many bags can he make?
Express your answer as an improper fraction.