M4 L8 Powerpoint

1. Multiplication and Area
Topic B: Concepts of Area Measurement
Module 4: Lesson 8
Objective: Find the area of a rectangle through
multiplication of the side lengths.

2. Fluency Practice
(11 minutes)
Multiply by 6 (8 minutes)
7 x 6 = _______ Let’s skip count by sixes.
6, 12, 18, 24, 30, 36, 42.
Let’s see how we can skip count down to find the
answer too. Start at 60.
60, 54, 48, 42
Continue with the following sequence: 9 x 6, 6 x 6, and
8 x 6.

3. Fluency Practice
(11 minutes)
Multiply by 6 pattern sheet (2 min)
Let’s practice multiplying by 6. Be sure to work left to
right across the page.

4. Fluency Practice
(11 minutes)
Group Counting (4 min)
• Fours to 40
• Sevens to 70
• Eights to 80
• Nines to 90

5. Application Problem (5 minutes)
Marnie and Connor both skip-count square units
to find the area of the same rectangle. Marnie
counts, “3, 6, 9, 12, 15, 18, 21.” Connor counts,
“7, 14, 21.” Draw what the rectangle might look
like, then label the side lengths and find the
area.

6. Application Problem (5 minutes)

7. Concept Development (34 minutes)
Part 1: Relate side lengths to area
How many rows are in the incomplete array? 4 rows.
How many square units are there in each row?
7 square units.

8. Concept Development (34 minutes)
Do we need to complete the array to find the
area of the rectangle? Why or why not?
How are the side lengths related to the area?

9. Concept Development (34 minutes)
Yes! You can multiply the
side lengths together to find
the area.
Can you multiply any 2 side
lengths together?
Right! You have to multiply
the side length that show
the number of rows times
the side length that shows
the number in each row.
Continue with the
following sequence:
6 by 5, 8 by 7, 9 by 6

10. Concept Development (20 minutes)
Part 2: Use side lengths to find area.
• What do you notice about this rectangle?

11. Concept Development (20 minutes)
Right, you know the side
lengths but there isn’t a grid
inside.
Do we have enough
information to find the area
of this rectangle even
without the grid lines? Yes!
We know both side lengths.
Write the multiplication
equation to find the area of
this rectangle.

12. Concept Development (20 minutes)

13. Concept Development (20 minutes)
• Part 2: Use area and side length to find
unknown side length.
What do you notice
about this rectangle?
Right! We know the area
but not both side lengths
one is unknown.

14. Concept Development (20 minutes)
Write a multiplication equation
to show how to find the area of
this rectangle. Use a question
mark for the unknown side
length. 3 x ? = 27
What is the value of the
question mark? 9! How do you
know? 3 times 9 equals 27!
So what is the side length? 9 cm
What is the related division
equation? 27 ÷ 3 = 9

15. Concept Development (20 minutes)
When you know the area and one side length of a rectangle, how
can you find the other side length?
Right! Think of it as a multiplication equation with an unknown factor
And/or divide the area by the known side length.

16. 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.

17. 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!

18. Homework
3-4 Lesson 8
Homework
Worksheet
Is Due Tomorrow!