Lesson plan

# Subtract fractions with unlike denominators by using area models

teaches Common Core State Standards MP4 http://corestandards.org/Math/Practice/MP4
teaches Common Core State Standards MP2 http://corestandards.org/Math/Practice/MP2
teaches Common Core State Standards MP1 http://corestandards.org/Math/Practice/MP1
teaches Common Core State Standards 5.NF.A.2 http://corestandards.org/Math/Content/5/NF/A/2
teaches Common Core State Standards 5.NF.A.1 http://corestandards.org/Math/Content/5/NF/A/1

# Subtract fractions with unlike denominators by using area models

Big Ideas: Because fractions are representations of equal parts, they can only be added or subtracted when those parts are of the same size or value. This lesson builds on students' work with subtracting fractions with like denominators. This task uses a discussion about sugar content in food and drink. Students determine how much more sugar one item has than another by subtracting fractions with unlike denominators. The mathematical concept in this lesson builds toward future use in solving ratio, rate, and proportion problems, and prepares students for work with greatest common factors and least common multiples in 6th grade algebra. Vocabulary: area model, numerator, unlike and like denominator, vertical, horizontal, teaspoons Special Materials: Colored pencils (optional) Teaspoon (optional) Measuring cups (optional) Sugar (optional)