Lesson objective: Compute sums and differences of fractions with different sized pieces whose values are between one and two.

This lesson helps to build fluency with adding and subtracting fractions with different sized pieces (unlike denominators). Fraction tape and number lines are used here because they highlight the idea of equivalency and adding/subtracting units. This work develops students' understanding that naming the sum or difference of two fractions as one number requires rewriting the fractions with same size pieces.

Students engage in Mathematical Practice 2 (Reason abstractly and quantitatively) as they make sense of quantities and their relationships in a problem situation when they reason about the magnitude of a sum. They will also exercise habits of quantitative reasoning by considering the units involved as they explore the meaning of the denominator and attend to the meaning of quantities.

**Key vocabulary:**

- Sum
- Difference
- Denominator
- Equivalent

**Special materials needed:**

- Students may need fraction tape for intervention