Lesson 12

The purpose of this lesson is for students to multiply one-digit numbers by multiples of 10.

The work of this lesson connects to previous work because students have used strategies based on properties of operations to multiply within 100. Now, students extend this work and consider place value to multiply one-digit numbers by multiples of 10. Students complete a problem in context in which they explore how 180 can be grouped into multiples of ten in different ways. Students analyze two strategies for multiplying a single-digit number by a multiple of ten, then complete similar problems using the strategy of their choice. Throughout the lesson the associative property is used as a strategy to think of problems like \(3 \times 60\) as 18 tens or \(18 \times 10\).

When students decompose multiples of ten in different ways as a strategy to multiply, they are looking for and making use of structure (MP7).

Students have used place value in past lessons to add and subtract. In this lesson, how do they begin using place value as a strategy to multiply multiples of 10?