Exercise 1 Page 151

There are many different ways to compare amounts or quantities. A ratio is a comparison of two quantities by division. For example, the ratio of $a$ to $b$ can be written in two different ways. We want to find the ratio of butterflies to caterpillars. We can start by writing the fraction that represents desired ratio. We will write the number of butterflies in the numerator and the number of caterpillars in the denominator. The greatest common factor of $3$ and $2$ is $1.$ This means that the fraction cannot be simplified. Finally, we can write this fraction as a ratio.