Unit 2, Lesson 1# Multiply multi-digit whole numbers and multiples of 10 using place value patterns and the distributive and associative properties.

EngageNY 60 min(s)

In this lesson, students begin to apply place value reasoning to multiply multi-digit numbers. They rewrite problems into unit form to multi-digit whole numbers and multiples of 10. For example, students solve 40 x 30 by writing it as four tens time three tens. Then they multiply four times 3 equals 12 and tens time tens equals hundreds. The answer is then 12 hundreds, or 1,200. Then students rewrite problems using the distributive and associative property to make the multiplication problem more accessible. Finally, students solve multiplication problems using the method of choice, and the class analyzes why the distributive method is useful for problems such as 451 x 8.