In this Cyberchase video, Kelly helps Bianca get a job working with her at a ribbon store. Bianca is so focused on taking advantage of her employee discount that she doesn't pay attention to Kelly's instructions. When it comes time to ring up a sale, Bianca struggles with adding measurements written as mixed numbers. Kelly helps by giving her a yardstick and some math strategies based on number sense. In the accompanying classroom activity, students participate in a cotton ball blowing event designed to give them practice adding fractions with different denominators.This resource is part of the Math at the Core: Middle School Collection.