**ratio**nal. [Latin comes in handy.] Thus, a rational number can be written as a

**ratio**, or fraction, which is the same thing: ½. Think of ratio this way: the quantitative relation between two amounts showing the number of times one value contains or is contained within the other. One is a rational number: it can be written as 1/1.

Example: the ratio of dogs to cats is 1 to 2. There is one dog contained in every two cats. Well, in English, we say, “one dog for every two cats”.

In Massachusetts, there are 1.6 million cats to 850,000 dogs. The ratio is 1,600,000/850,000, which is 160/85. Just cross out the four zeros on top and the four zeros on the bottom. Use the calculator and the result is in decimal form: 1.88 ferocious felines, almost two, for every friendly Fido. Figures rounded. These numbers are rational numbers.

The owners, however, might be irrational.