Lesson objective: Solve multistep problems involving sums and differences of fractions with different sized pieces.
This lesson provides an opportunity for students to apply their knowledge and understanding of addition and subtraction of fractions with different sized pieces to a reallife situation. Students are asked to compute the amount of paper needed for decorating a classroom, then identify two values from a list that may be used to find the missing value.
Key Concept students will use:

We can use the magnitude of fractions to be added or subtracted to estimate the sum or difference as less than or greater than some whole number, or to tell what two whole numbers the result should fall between.
 Naming the sum or difference of two fractions as one number requires rewriting the fractions with same size pieces.
Skills students will use:
 Find equivalent fractions (Grade 3, Unit 10)
 Calculate sums and differences of fractions in multistep expressions
Students engage in Mathematical Practice 4 (Model with mathematics) as they apply the mathematics they know to solve problems arising in everyday life. Students use tools, such as tape diagrams, to analyze relationships between quantities and draw mathematical conclusions.
Key vocabulary:
 sum
 difference
 equivalent
 decompose
 denominator
Special materials needed:
 Students may need fraction tape for intervention.