M1 L15 Powerpoint

1. Module 1: Lesson 15
Relate arrays to tape diagrams
to model the commutative
property of multiplication

2. Fluency Practice
Multiply by 4
(8 minutes)
• Write 4 x 5=
Let’s skip count by 4 to find the answer!
• Write 4 x 4 =
Let’s skip count by 4 to find the answer!
Repeat the process for 4 x 3 =
Complete the practice sheet multiplying by 4. Be sure to
work left to right across the page.

3. Fluency Practice
Group Counting
(3 minutes)

4. Application Problem
(5 minutes)
Mark spends $16 on 2 video games. Each game
costs the same amount. Find the cost of each game.
A cell phone is about 4 inches long. About how long are 9 cell
phones laid end to end?
Complete a RDW to solve this problem, using a tape diagram. Be
sure to label the tape diagram!

6. Concept Development
(34 minutes)
Personal white boards*
Distribute blank paper with 1/3 folded
Draw an array with 2 rows and 4 columns
above the fold in your paper. Use the array to
remind your partner about what the
commutative property is. Turn it if you need to.
Use the commutative property to write two
multiplication equations for the array. Write
them on the left side of the paper below the
fold, one above the other.

7. Concept Development
(34 minutes)
Next to each equation, draw
and label a tape diagram to
match. Make sure the
diagrams are the same size
because they both represent
the same total.
Explain to a partner how your
tape diagrams relate to the
array.
The array shows
commutativity, and so do the
tape diagrams as we compare
them. Why is that true?

8. Concept Development
(34 minutes)
Repeat the process with 9 x 4
5 x 4
Draw arrays to match the equation
Write two equations for the array
Draw and label tape diagrams to represent the commutativity of each set of
facts.
4 x 7
Draw arrays to match the equation
Write two equations for the array
Draw and label tape diagrams to represent the commutativity of each set of
facts.

9. Concept Development
(34 minutes)
Why is it that 1 array can show two multiplication
sentences, but 1 tape diagram can only show one
multiplication sentence?

10. Problem Set (10 minutes)
You have 10 minutes to complete the problem set pages.
Debrief (10 minutes)
Let’s review your solutions for the problem set.
Exit Ticket (3 minutes)

11. Exit Ticket
(3 minutes)
This is where you are going to show
us that you understand what we learned today!
We will learn if you are ready for the next lesson!

12. Homework
Lesson 15 Homework
Worksheet
Is Due Tomorrow!