We use ratios to compare two quantities or numbers. When ratios are used to compare two quantities of different units, they are known as rates. For example, we can make a comparison of distance run with the running time. Suppose, Adam ran 10 km in 45 minutes. Here, the ratio of distance to time is the required rate. These figures can be easily represented with a double number line.
Grade 6
Ratios And Rates
6.RP.A.3.A