# Lesson Plan: Word Problems: Adding and Subtracting Mixed Numbers with Unlike Denominators Mathematics • 5th Grade

This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to solve one- and two-step word problems involving adding and subtracting up to three mixed numbers with different denominators.

#### Objectives

Students will be able to

• write a number sentence to describe a word problem,
• choose an appropriate method to add or subtract mixed numbers with unlike denominators to solve word problems,
• solve a one-step word problem by adding or subtracting mixed numbers with unlike denominators,
• solve a two-step word problem by adding or subtracting mixed numbers with unlike denominators,
• give the answer to a word problem in its simplest form.

#### Prerequisites

Students should already be familiar with

• finding common denominators of fractions using multiplication and division up to ,
• adding and subtracting mixed numbers and proper fractions with unlike denominators.

#### Exclusions

Students will not cover

• finding the lowest common denominator using prime factors.