All the solutions provided in McGraw Hill My Math Grade 3 Answer Key PDF Chapter 13 Lesson 4 Measure Area will give you a clear idea of the concepts.
McGraw-Hill My Math Grade 3 Answer Key Chapter 13 Lesson 4 Measure Area
Area is the number of square units needed to cover a figure without overlapping. Sometimes you need to count the number of half-square units covered by the figure.
Math in My World
Example 1
In art class, Halley drew the figure at the right on grid paper. What is the area of the figure Halley drew?
1. Count the number of whole squares.
There are ____________ whole squares.
2. Count the number of half-squares.
There are 2 half-squares. Two halves equal one whole.
3. Add.
So, the area is ___________ square units.
Answer:
There are 14 whole squares.
There are 2 half-squares.
Two halves equal one whole.
Know add the whole squares and 2 half squares.
So, the area is 15 square units.
Example 2
Rafael created the geoboard figure at the right to represent a design he created. One square unit on the geoboard represents one square centimeter on the design. What is the area of the design?
1. Count the number of whole squares.
There are _____________ whole squares.
2. Count the number of half-squares.
There are ___________ half-squares. Eight halves equal four wholes.
3. Add.
So, the area is ______________ square units.
The area of the design is ____________ square centimeters.
Answer:
In the figure,
There are 8 whole squares.
There are 8 half-squares.
Eight halves equal four wholes.
So, the area is 12 square units.
The area of the design is 12 square centimeters.
Talk Math
A figure is covered by 10 whole squares and some half-squares. If the area is 12 square units, how many half-squares are there? Explain.
Answer:
Given that,
A figure is covered by 10 whole squares and some half-squares.
If the area is 12 square units.
It means 12 – 10 = 2 square units.
2 square units = 4 half-square units.
Therefore there are 4 half squares are there.
Guided Practice
Find the area of each figure.
Question 1.
____________ square units
Answer:
In the figure,
There are 3 whole squares.
There are 3 half-squares.
Three halves equal to 1 whole and 1 half squares
So, the area is 4.5 square units.
Question 2.
____________ square units
Answer:
In the figure,
There are 4 whole squares.
There are 2 half-squares.
Two halves equal to one whole.
So, the area is 5 square units.
Independent Practice
Find the area of each figure.
Question 3.
The area is _____________ square units.
Answer:
In the figure,
There are 4 whole squares.
There are 4 half-squares.
Four halves equal to two wholes.
So, the area is 6 square units.
Question 4.
The area is _____________ square units.
Answer:
In the figure,
There are 2 whole squares.
There are 2 half-squares.
Two halves equal one wholes.
So, the area is 3 square units.
The area is 3 square units.
Question 5.
The area is _____________ square units.
Answer:
In the figure,
There are 6 whole squares.
There are 4 half-squares.
Four halves equal two wholes.
So, the area is 6 + 2 = 8 square units.
The area is 8 square units.
Question 6.
The area is _____________ square units.
Answer:
In the figure,
There are 4 whole squares.
There are 8 half-squares.
Eight halves equal four wholes.
So, the area is 4 + 4 = 8 square units.
The area is 8 square units.
Find the area of each shaded region if one square unit represents one square inch.
Question 7.
The area is _____________ square inches.
Answer:
In the figure,
There are 12 whole squares.
So, the area is 12 square inches.
Therefore the area is 12 square inches
Question 8.
The area is _____________ square inches.
Answer:
In the figure,
There are 9 whole squares.
There are 3 half-squares.
Three halves equal one whole and one half square unit.
So, the area is 9 + 1 + 0.5 square inches.
The area is 10.5 square inches.
Question 9.
The area is _____________ square inches.
Answer:
In the figure,
There are 8 whole squares.
There are 4 half-squares.
Four halves equal Two wholes.
So, the area is 8 + 2 = 10 square units.
Therefore the area is 10 square inches.
Question 10.
The area is _____________ square inches.
Answer:
In the figure,
There are 8 whole squares.
So, the area is 8 square units.
Therefore the area is 8 square inches.
Problem Solving
Question 11.
Denitra’s family is building a stone walkway around their backyard. One square unit on the drawing at the right represents one square foot of the stone walkway. What is the area of the stone walkway?
Answer:
Given that
Denitra’s family is building a stone walkway around their backyard.
In the figure,
There are 18 whole squares.
So, the area is 18 square units.
Therefore the area is 18 square inches.
Question 12.
Mathematical PRACTICE Use Math Tools Luisa is helping to tile a hallway. How many square tiles will be needed to fill the area?
Answer:
Given that,
1 unit = 1 tile.
The total number of units is 3 x 5 = 15 units.
The total number of tiles is 15.
Here we have 1 tile.
Therefore 15 – 1 = 14.
Therefore there are 14 square tiles will be needed to fill the area.
HOT Problems
Question 13.
Mathematical PRACTICE Reason Use the grid to draw two different figures that have the same area.
Answer:
The two different figures are
In the figure1,
There are 30 whole squares.
So, the area is 30 square units.
In the figure2,
There are 30 whole squares.
So, the area is 30 square units.
Therefore the two different figures have the same area.
Question 14.
Mathematical PRACTICE Plan Your Solution A rectangular room is 10 units wide by 14 units long. Find the area and perimeter of the room.
Answer:
Given that,
The length of the rectangular room is 14 units.
The wide of the rectangular room is 10 units.
The area of the rectangular room is l x b = 14 x 10 = 140 units.
The perimeter of the rectangular room is 2(l + b) = 2(14 + 10) = 2(24) = 48 units.
Question 15.
Building on the Essential Question How is the operation of addition related to finding area?
Answer:
The operation of the addition is related to finding the area by counting the square units in the shape of the figure.
McGraw Hill My Math Grade 3 Chapter 13 Lesson 4 My Homework Answer Key
Practice
Find the area of each figure.
Question 1.
The area is ______________ square units.
Answer:
In the figure,
There are 12 whole squares.
There are 4 half-squares.
Four halves equal Two wholes.
So, the area is 12 + 2 = 14 square units.
Therefore the area is 14 square inches.
Question 2.
The area is ______________ square units.
Answer:
In the figure,
There are 6 whole squares.
There are 2 half-squares.
Two halves equal one wholes.
So, the area is 6 + 1 = 7 square units.
Therefore the area is 7 square inches.
Find the area of each shaded region if one square unit represents one square meter.
Question 3.
The area is ______________ square meters.
Answer:
In the figure,
There are 8 whole squares.
So, the area is 8 square units.
Therefore the area is 8 square inches.
Question 4.
The area is ______________ square meters.
Answer:
In the figure,
There are 12 whole squares.
So, the area is 12 square units.
Therefore the area is 12 square inches.
Problem Solving
For Exercises 5 and 6, refer to the drawing at the right which represents the area of Elaine’s bedroom.
Question 5.
What is the area of Elaine’s bedroom ¡n square units?
Answer:
In the figure,
There are 14 whole squares.
There are 2 half-squares.
Two halves equal one wholes.
So, the area is 14 + 1 = 15 square units.
Question 6.
Mathematical PRACTICE Look for a Pattern If each square unit represents 5 square feet, what is the area of Elaine’s bedroom in square feet? Use repeated addition.
Answer:
In the figure,
There are 14 whole squares.
There are 2 half-squares.
Two halves equal one wholes.
So, the area is 14 + 1 = 15 square units.
Each square unit represents 5 square feet,
Therefore 15 x 5 = 75 square feet.
Vocabulary Check
Question 7.
Describe area in your own words.
Answer:
The area is defined as the total surface of an object.
Test Practice
Question 8.
What is the area of the figure at the right?
(A) 12 square units
(B) 13 square units
(C) 14 square units
(D) 16 square units
Answer:
In the figure,
There are 12 whole squares.
There are 2 half-squares.
Two halves equal one wholes.
So, the area is 12 + 1 = 13 square units.
Option B is the correct answer.