Do the Math Here's an example of how to calculate the surface area-to-volume ratio of the cube shown at the right. Sample Problem You Try It A Calculate the surface area. 7 Calculate What is the surface area-to-volume ratio of a cube whose sides are 3 cm long? surface area of cube = A Calculate the surface area. number of faces x area of one face surface area of cube = 6(2 cm x 2 cm) surface area of cube = 24 cm? B Calculate the volume. B Calculate the volume. volume of cube = side x side x side volume of cube = 2 cm x 2 cm x 2 cm volume of cube = 8 cm? C Calculate the surface area-to-volume ratio. C Calculate the surface area-to-volume ratio. A ratio is a comparison between numbers. It can be written by placing a colon between the numbers being compared. surface area : volume = 24 cm: 8 cm surface area : volume =3 cm?: 1 cm