# MathBench>Miscellaneous

## More uses for Ratios

Often ratios are used to compare a part of a mixture to another part of a mixture. For example, classic pound cake is made with

• 1 pound butter
• 1 pound eggs
• 1 pound sugar
• 1 pound flour

The ratio of any two ingredients in this cake (say, sugar:butter) is 1:1. On the other hand, a “lowfat” pound cake has

• 12 oz corn-oil butter
• 10 oz eggs
• 13 oz flour
• 21 oz sugar

Now what is the ratio of sugar to butter?

What is the ratio of carb ingredients (sugar and flour) to fat ingredients (eggs and butter)?

Notice that I added some things up before doing the division. This is natural if I’m interested in categories of ingredients in the mixture.

In case you’re missing the connections to biology here…

• blood is a mixture of components
• chemical reactions require (and produce) mixtures of molecules
• animals diets, and individual foods, consist of a mixture of nutrients

We’ll get to some of these lovely examples later in the module.