We included **HMH Into Math Grade 4 Answer Key**** PDF** **Module 9 Lesson 1 Apply the Area Formula to Rectangles** to make students experts in learning maths.

## HMH Into Math Grade 4 Module 9 Lesson 1 Answer Key Apply the Area Formula to Rectangles

I Can find the area of a rectangle by using the formula for area.

**Spark Your Learning**

Making banners is a very old craft. Banners are usually made of cloth and can have a symbol, logo, slogan, or any other message. How can you find the area of each banner?

Answer:

The area can be calculated by using the formula,

Area = Length x width.

for the first banner

Area = 5 x 8 = 40 square feet

for the second banner,

Area = 4 x 10 = 40 square feet.

**Show your thinking.**

**Turn and Talk** What do you notice about the perimeter and area of each banner?

Answer:

Perimeter gives the total circumference of the rectangle whereas, Area gives the total number of units that fit in the given figure or banner.

**Build Understanding**

1. Sports fans use banners to show support. How can you find the area of the banner?

A. What does it mean to find the area of a flat surface?

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Answer:

Area is **a measure of how much space there is on a flat surface**.

To find the area, think about the measure of the sides of the rectangle.

B. How many unit squares make up the length and width of the rectangle?

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28 unit squares make up the length and width of the rectangle

C. Count the number of unit squares to find the area. __________________________________

Answer:

28 unit squares required to find the area.

D. What is the relationship between the length and width and the area? __________________________________

Answer:

the relationship between the length and width and the areais

Area = Length X Width.

E. How can you describe a mathematical rule or formula that you would use to find the area (A) of the rectangle? Write the formula. Represent the length with l and the width with w.

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Answer:

Area = Length X Width.

**Connect to Vocabulary**

You can also write the formula for the area (A) of a rectangle as A = b × h. Think of the base (b) of a rectangle as the measure of any side. The height (h) of the rectangle is the measure of a side perpendicular to the base.

F. How can you use the area formula to find the area of the rectangle?

A = l × w

A = __ × ___

A = ___

Answer:

A = l × w

A = 7 x 4

A = 28 square units.

G. The rectangle has an area of ___ square units.

Answer:

The rectangle has an area of 28 square units

**Step It Out**

2. The Hawks’ fans are making a giant banner for a competition. The banner has the dimensions shown. What is the area of the banner?

A. Write the formula that you can use to solve the problem.

Answer:

Area = Length x Width

B. Write the measure of the length, l, and the width, w, of the banner.

Answer:

From the figure,

Length = 5 meters

Width = 7 meters.

C. Find the area of the banner.

Answer:

From formula,

Area = Length x width

Area = 5 x 7 = 35 square meters.

D. The area of the banner The area is ___ square meters.

Answer:

The area of the banner The area is 35 square meters.

Area = Length x width

Area = 5 x 7

Area = 35 square meters.

**Turn and Talk** How would the area of the banner change if the banner was turned so that the width is 7 meters and the length is 5 meters?

Answer:

there will be no change in the area of the rectangle. Because, 5 x 7 = 7 x 5 = 35 square meters only.

**Check Understanding Math Board**

Question 1.

Mr. Nielsen is going to buy sod for a portion of his yard, but first, he must know the area of the surface that he wants to cover. What is the area?

___________________

Answer:

From the figure,

Area = Length x width

Area = 18 x 25

Area = 450 square feet.

Therefore, Area of the figure is 450 square feet.

**Find the area.**

Question 2.

Answer:

From the figure,

Area = Length x width

Area = 9 x 6

Area = 54 square m.

Therefore, Area of the figure is 54 square m.

Question 3.

Answer:

From the figure,

Area = Length x width

Area = 10 x 10

Area = 100 square ft.

Therefore, Area of the figure is 100 square ft.

**On Your Own**

Question 4.

Jason has a sticker on a folder. What is the area of the sticker?

Answer:

From the figure,

Area = Length x width

Area = 7 x 3

Area = 21 square cm.

Therefore, Area of the sticker on folder is 21 square cm.

Question 5.

Lisa is setting square tiles on a backsplash. What is the area of each tile?

Answer:

From the figure,

Area = Length x width

Area = 5 x 5

Area = 25 square in

Therefore, Area of the each tile is 25 square in.

Question 6.

**Reason** Mr. Wells knows that the area of the square floor in a toolshed is 36 square feet. What is the length of one of the sides? How do you know?

Answer:

We know,

Area of square = side x side

36 = side x side

side = square root of 36 = 6

Therefore, length of one of the sides = 6 ft.

**Use Structure Find its area.**

Question 7.

Answer:

From the figure,

Area = Length x width

Area = 14 x 6

Area =84 square cm

Therefore, Area of the figure is 84 square cm.

Question 8.

Answer:

From the figure,

Area = Length x width

Area = 3 x 11

Area = 33 square in.

Therefore, Area of the figure is 33 square in.

Question 9.

Answer:

From the figure,

Area = Length x width

Area = 8 x 8

Area = 64 square cm.

Therefore, Area of the figure is 64 square cm.

**I’m in a Learning Mindset!**

What parts of solving problems using the area formula am I comfortable with?

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