# Ratios

A ratio is a comparison of two numbers. It can be written with a colon ( $1:5$ ), or using the word "to" ( $1$ to $5$ ), or as a fraction: $\frac{1}{5}$

Example:

Write the ratio of blue dots to red dots in the figure.

There are $6$ blue dots and $4$ red dots.

Write the ratio as a fraction.

$\frac{6}{4}$

$\frac{3}{2}$

So the ratio of blue dots to red dots is $3:2$ .

(Note that the ratio of red dots to blue dots is the reciprocal : $\frac{2}{3}$ or $2:3$ .)