Unit 4, Lesson 21# Explain the size of the product, and relate fraction and decimal equivalence to multiplying a fraction by 1.

EngageNY 60 min(s)

In this lesson, students begin reasoning about the size of products when quantities are multiplied by one. They relate their previous work with equivalent fractions to interpreting multiplication by n/n as multiplication by 1. For example, 2/2 of 3/4 is 6/8, which is equivalent to 3/4. Then students rewrite fractions as decimals using equivalent fractions. For example, 1/5 = 2/10 = 0.2.