Lesson Plan: Subtracting Fractions with Unlike Denominators

In this seventh lesson of the Adding and Subtracting Fractions Unit, students will learn how to subtract fractions with unlike denominators. This essential skill builds on their understanding of finding common denominators and equivalent fractions, enabling them to successfully subtract fractions with different denominators.

Students will:

• Understand why fractions with different denominators cannot be subtracted directly
• Use the Least Common Denominator (LCD) to rewrite fractions with a common denominator
• Convert fractions into equivalent fractions before subtracting
• Practice subtracting fractions and simplifying their answers when necessary
• Apply their knowledge to solve real-world fraction subtraction problems

Designed for grades 3-5, this lesson aligns with Common Core standards and reinforces students’ understanding of multiple fraction concepts, including equivalent fractions and least common multiples. Mastering this skill will prepare students for more advanced fraction operations.

This is the seventh lesson in a ten-part unit on adding and subtracting fractions. Future lessons will introduce working with mixed numbers and solving fraction word problems.

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