Lesson Plan: Subtracting Mixed Numbers When Denominators Are Multiples
This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to subtract two mixed numbers whose denominators are multiples of the same number.
Objectives
Students will be able to
- subtract one mixed number from another when the denominator of one is a multiple of the denominator of the other,
- represent calculations with models including bar models,
- subtract by breaking apart one of the mixed numbers and regrouping if necessary,
- subtract by converting to improper fractions,
- decide whether one method is easier than another.
Prerequisites
Students should already be familiar with
- subtracting fractions with the same denominator,
- finding equivalent fractions,
- writing fractions in the simplest form,
- finding common denominators.
Exclusions
Students will not cover
- finding the lowest common denominator.
