Unit 2, Lesson 4# Convert numerical expressions into unit form as a mental strategy for multi-digit multiplication.

EngageNY 60 min(s)

In this lesson, students continue to decompose numbers, with the goal now of evaluating expressions mentally. They use tape diagrams to help in the process. For example, students solve 8 x 31 by decomposing into 30 eights plus 1 eight. Students solve 30 eights is easy, 240. 240 + 8 = 248.