Multiplication as Scaling

Teach your students to interpret multiplication as scaling. In this lesson, students will learn to predict the size of a product, using one factor as scale.
Need extra help for EL students? Try the Discussing Scaling with Fractions pre-lesson.
View aligned standards
Need extra help for EL students? Try the Discussing Scaling with Fractions pre-lesson.

Learning Objectives

Students will be able to interpret multiplication as scaling by comparing the size of a factor to the size of the product, without solving the equation.

The adjustment to the whole group lesson is a modification to differentiate for children who are English learners.

Introduction

(5 minutes)
• Write a multiplication problem on the board, like 3 x 6 = 18.
• Point out that the product is greater than either factor, and explain, "When we multiply whole numbers, the product is greater than the factors. In this problem, 18 is six times larger than three."
• Tell students that today we are going to think about multiplication as a way to scale, or compare the size of numbers.

Beginning

• Allow them to use their home language (L1) or new language (L2) in their discussions.
• Give students vocabulary cards or visuals for the following words: multiplication, whole number, greater, larger, product, factor, and scale.
• Allow them to use their L1 or L2 to restate the meaning of the word scale in regards to multiplication.

Intermediate

• Write the academic language they can use throughout the lesson on the board as you introduce the language.
• Provide a realistic scenario that involves 3 x 6 = 18 and draw a visual to accompany the scenario. Ask for them to restate your example, in particular your explanation of 18 being 6six times bigger than three.