Lesson Plan

Subtracting Fractions with Different Denominators

Getting ready to subtract fractions? This lesson reviews how to subtract like denominators and teaches students how to subtract unlike denominators. The focus is on understanding the process and reasoning behind each step.
Need extra help for EL students? Try the Subtracting Fractions Justifications pre-lesson.
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Need extra help for EL students? Try the Subtracting Fractions Justifications pre-lesson.

Learning Objectives

Students will be able to subtract fractions with unlike denominators.

The adjustment to the whole group lesson is a modification to differentiate for children who are English learners.
EL adjustments

Introduction

(5 minutes)
Subtracting Fractions: Unlike DenominatorsSubtracting with Unlike Denominators Word Problem
  • Write ⅘ − ⅕ on the board and ask students to solve for the problem on their whiteboards using whatever method they choose.
  • Have students share their answers with their elbow partner. Gather their background knowledge by asking them questions about the numerator, denominator, and how they got their answer.
  • Ask for a volunteer to come to the board and solve the problem using a number line, area model, or simply subtracting one-fifth from four-fifths.
  • Tell students that today they'll build on their understanding of subtracting fractions with like denominators to subtract fractions with unlike denominators.

Beginning

  • Allow students to use their home language (L1) or new language (L2) in their discussions about the subtraction problem.
  • Provide a real-world example they are familar with so they can fully understand the new terms.

Intermediate

  • Write the academic language they can use throughout the lesson on the board as you introduce the language.