Ratio

A ratio is a comparison of two quantities. The ratio \(\textcolor{colordef}{3}\) to \(\textcolor{colorprop}{2}\) can be expressed as \(\textcolor{colordef}{3}:\textcolor{colorprop}{2}\) or \(\dfrac{\textcolor{colordef}{3}}{\textcolor{colorprop}{2}}\).

A part-part ratio compares two distinct parts of a whole.$$\textcolor{colordef}{\text{Part 1}}:\textcolor{colorprop}{\text{Part 2}}$$

For one bowl of fruit juice, there are \(\textcolor{colordef}{3}\) cherries and \(\textcolor{olive}{2}\) apples.The ratio of cherries to apples is \(\textcolor{colordef}{3}:\textcolor{olive}{2}\).

A Part-whole ratio compares one part of a whole to the whole.$$\textcolor{colordef}{\text{Part 1}}:\textcolor{olive}{\text{Whole}}\text{ or }\textcolor{colorprop}{\text{Part 2}}:\textcolor{olive}{\text{Whole}}$$

If a juice is made with \(\textcolor{yellow}{1}\) lemon and \(\textcolor{orange}{2}\) oranges, find the ratio of oranges to the total number of fruits.

The ratio of red apples to all apples is \(\dfrac{2}{4}\), which can be simplified to \(\dfrac{1}{2}\) (half of the apples are red).

To find the number of apples corresponding to \(\dfrac{1}{2}\) of 4 apples:

• Draw the fraction:
• Count the apples in the colored part: there are 2 apples.