Intro to Ratios

A ratio is simply a comparison between two quantities. It shows how much of one thing there is compared to another. For example, if you have 4 squares and 2 circles, the ratio of squares to circles is 4 to 2.

Ratios can describe different types of comparisons. A Part:Part ratio compares one group to another group (like squares to circles). A Part:Whole ratio compares one group to the total (like triangles to the total number of shapes).

You can write ratios in three different ways: using the word "to" (4 to 2), using a colon (4:2), or as a fraction $4/2$. All three mean the same thing! The numbers in a ratio are called terms.

Fun Fact: When someone says "For every 3 triangles there are 9 total shapes," they're using a Part:Whole ratio of 3:9, which can be simplified to 1:3!