7th Grade Math

Square Roots

PART A B CDE

Multi-Part

Lesson 3

Get ConnectED

GLE 0706.2.5

Understand and work with

squares, cubes, square roots

and cube roots. SPI 0706.2.3

Use rational numbers and

roots of perfect squares/

cubes to solve contextual

problems. Also addresses

GLE 0706.1.8.

Lesson 3B Square Roots 53

Squares and Square

Roots

WATERMELON Farmers are now growing

square watermelons. Yancy cut a piece of

square watermelon with a side length of

5 inches. What is the area of the piece of

watermelon?

Recall the area of a square can be found by

5 units

5 units 25 units^2

multiplying the lengths of two sides. The area of

the square at the right is 5 · 5 or 25 square units.

The product of a number and itself is the square

of that number. So, the square of 5 is 25.

So, the area of Yancy’s piece of watermelon is 25 square inches.

Find Squares of Numbers

Find the square of 3.

3 units

9 units^2 3 units

3 · 3 = 9 Multiply 3 by itself.

So, the square of 3 is 9.

Find the square of 28.

Method 1 Use paper and pencil.

28 Multiply 28 by itself.

× 28

224

+ 560

784

Method 2 Use a calculator.

28 784

So, the square of 28 is 784.

Find the square of each number.

a. 8 b. 12 c. 23

Numbers like 9, 16, and 225 are called square numbers or perfect

squares because they are squares of whole numbers.

Main Idea

Find squares of

numbers and square

roots of perfect

squares.

Vocabulary

square

perfect square

square root

radical sign

V

s

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