**Objective: **

Subtract fractions with unlike denominators using equivalent representations that use equal-sized pieces.

This optional activity can be used after Unit 3 Lesson 6.

**Math concept addressed:**

In this Guided Collaborative Task, students will use their knowledge and understanding of equivalent fractions to figure out differences in fractions with unlike denominators. Students will figure this out by using fraction bars to find equal-sized pieces that can be easily subtracted.

Under the “Additional materials” tab, you’ll find grid paper that may be used as students draw fraction bars to find equal sized pieces that can be easily subtracted.

**Prior knowledge needed: **

Students bring prior knowledge of adding and subtracting fractions with unlike denominators by rewriting the fractions in equivalent forms.

**How students will collaborate:**

Collaboration happens through a collaborative structure called "Each One, Pick One". Students will pick one of the two given strategies to defend as a good strategy to use to solve this task.

**Mathematical practice featured:**

Students engage in Mathematical Practice 4 (Model with mathematics) as they create visual representations of the fractions and notice that similar sized pieces make it easier to find the difference between two fractions with unlike denominators.

**Key vocabulary:**

- denominator

- equal-sized

- equivalent fraction