# Lesson 15

An Assortment of Fractions

### Lesson Purpose

The purpose of this lesson is for students to use equivalence to reason about problems that involve combining or removing fractional amounts.

### Lesson Narrative

In a previous unit, students learned to recognize and generate equivalent fractions. Earlier in this unit, they learned to add and subtract fractions with the same denominator, seeing these operations as joining and separating parts of the same whole. In this lesson, students encounter situations that involve combining and removing fractions with different denominators (limited to 2, 3, 4, 6, and 8), prompting them to rely on their understanding about equivalence to reason about the problems. This work prepares students to use equivalent fractions to join tenths and hundredths in upcoming lessons.

Students are not expected to reason symbolically, or to write fractional expressions with different denominators and then rewrite them with a common denominator. Instead, they reason using their intuitive understanding of equivalence, which they have begun to build since grade 3, and with the support of visual representations as needed.

• Engagement
• MLR1

Activity 2: Stacks of Blocks

Teacher Facing

### Student Facing

• Let’s find the heights of some stacked objects.

Building On

Building Towards

### Lesson Timeline

 Warm-up 10 min Activity 1 15 min Activity 2 20 min Lesson Synthesis 10 min Cool-down 5 min

### Teacher Reflection Questions

How did the activities in today’s lesson prepare students to add tenths and hundredths in the next lesson? How will you connect the ideas around equivalent fractions to upcoming work?

### Suggested Centers

• Jump the Line (2–5), Stage 2: Add and Subtract Tenths and Hundredths (Addressing)