Math Unit 4 Lesson 6

Draw rows and columns to determine the are of a rectangle given an incomplete array

Skip Count!

Skip Count By 6s To 60 … 6 12 18 24 3036 42 48 54 60

Skip Count By 7s To 70 … 7 14 21 28 35

42 49 56 63 70

Skip Count by 8s to 80 … 8 16 24 32 40

48 56 64 72 80

Skip Count by 9s to 90 … 9 18 27 36 45

54 63 72 81 90

Products In an Array

There are 15 tiles. How many rows are there?

5 x ____ = 153

Products In an Array

There are 24 tiles. How many rows are there?

6 x ____ = 244

Products In an Array

There are 40 tiles. How many rows are there?

8 x ____ = 405

Products In an Array

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2 x 6 6 x 2

Products In an Array

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4 x 9 9 x 4

Products In an Array

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3 x 7 7 x 3

Problem of the DayHuma has 4 bags of square inch tiles. Each bag contains 6 tiles. Huma uses the tiles to measure the area of a rectangle on her homework. After covering the rectangle she has 4 tiles left. What is the area of the rectangle?Step 1: How many tiles does she have?

6 6 6 6

24

Step 2: How many tiles does she use?

24 - 4 = 20The area of the rectangle is 20 sq.

inches.

Concept DevelopmentHow can an array of square units help you find the area of a rectangle?

Count the squares inside the rectangle

Skip count the rows to find the total

What do you notice about this array?Some of the square units are missing.

What do you see on the top row?

Look at the second row.

Can you use the second row to help you know how many square units are on the top row?

Talk to your partner. How can you use the top row to figure out how many square units will fit in each of the rows below?

How do you know?

Let’s fill in the missing lines of the array.How many rows of 6 are in this array?

What equation can be used to find the area of the rectangle?

4 x 6 = 24

Concept Development

Can we estimate to draw square units inside the rectangle?

Concept Development

Yes!It might take longer because fewer units are given.

Concept Development

Talk to your partner.What is a quicker way to find the total area?

Concept Development

We could find the number of rows & columns and multiply.

Concept Development

How can we find the number of rows & columns?

We can use the existing lines to fill in the first row & column!

Concept Development

What number sentence can be used to find the area?

5 x 6 = 30

Concept Development

5 x 6 = 30

The area is 30 square units!

Problem Set!

Let’s

figur

e it

out!