Instructions
This worksheet explores the connection between squaring a number (finding a perfect square) and finding the square root of that number. These two operations are inverses of each other—they undo one another.
- Review the definitions and the example table in Section 1.
- Complete the calculation problems in Sections 2 and 3.
- Apply your knowledge to the real-world scenarios in Section 4.
Section 1: The Inverse Relationship
Definition 1: Squaring a Number When you square a number, you multiply it by itself. The result is called a Perfect Square.
Definition 2: Square Root The square root of a perfect square is the original number that was multiplied by itself. Finding the square root undoes the squaring operation.
The Perfect Square / Square Root Connection
| Start Number | Operation (Squaring) | Perfect Square | Inverse Operation (Square Root) | Result |
|---|---|---|---|---|
| 5 | 5 x 5 | 25 | Square root of 25 | 5 |
| 8 | 8 x 8 | 64 | Square root of 64 | 8 |
| 10 | 10 x 10 | 100 | Square root of 100 | 10 |
| 12 | ||||
| 15 | ||||
| 20 |
Section 2: Finding Perfect Squares (Squaring)
Calculate the following squares. Show the multiplication steps.
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9 squared (9 x 9): Answer: ____
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11 squared (11 x 11): Answer: ____
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16 squared (16 x 16): Answer: ____
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25 squared (25 x 25): Answer: ____
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If a large parking lot is 30 units wide and 30 units long, what is its total area (the perfect square)? Calculation: ___ Area: ____
Section 3: Finding Square Roots (Inverse Operation)
Determine the positive whole number that was multiplied by itself to get the following perfect squares. (Hint: What number times itself equals the Perfect Square?)
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Square Root of 49: Answer: ____ (because 7 x 7 = 49)
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Square Root of 121: Answer: ____
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Square Root of 225: Answer: ____
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Square Root of 400: Answer: ____
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Square Root of 1,600: Answer: ____
Section 4: Real-World Application (Area and Sides)
In geometry, if a shape is a perfect square, its area is a perfect square number. The side length is the square root of the area.
Problem Set A: Finding the Area (Squaring)
| Side Length of a Square Garden | Calculation (Side x Side) | Area (Perfect Square) |
|---|---|---|
| Example: 7 feet | 7 x 7 | 49 square feet |
| 6 meters | ||
| 14 inches | ||
| 50 centimeters |
Problem Set B: Finding the Side Length (Square Roots)
| Area of a Square Room | Calculation (Square Root of Area) | Side Length |
|---|---|---|
| Example: 81 square meters | Square root of 81 | 9 meters |
| 144 square units | ||
| 625 square units | ||
| 900 square units |
Section 5: Challenge and Extension
These problems require two steps: finding the square root, and then using that number for another calculation.
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A square bulletin board has an area of 1,024 square inches. a) What is the length of one side of the bulletin board? (Find the square root). Side Length: ____ b) If you wanted to put trim around the entire perimeter (all four sides), how many total inches of trim would you need? Perimeter Calculation: ___ Perimeter: ____
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The square root of a certain perfect square (X) is 18. What is the value of X? (Hint: Use the inverse operation to solve). X = ___
Answer Key
Section 1: The Inverse Relationship (Completed Table)
| Start Number | Operation (Squaring) | Perfect Square | Inverse Operation (Square Root) | Result |
|---|---|---|---|---|
| 12 | 12 x 12 | 144 | Square root of 144 | 12 |
| 15 | 15 x 15 | 225 | Square root of 225 | 15 |
| 20 | 20 x 20 | 400 | Square root of 400 | 20 |
Section 2: Finding Perfect Squares
- 81
- 121
- 256
- 625
- Calculation: 30 x 30. Area: 900
Section 3: Finding Square Roots
- 7
- 11
- 15
- 20
- 40
Section 4: Real-World Application
Problem Set A
| Side Length of a Square Garden | Calculation (Side x Side) | Area (Perfect Square) |
|---|---|---|
| 6 meters | 6 x 6 | 36 square meters |
| 14 inches | 14 x 14 | 196 square inches |
| 50 centimeters | 50 x 50 | 2,500 square centimeters |
Problem Set B
| Area of a Square Room | Calculation (Square Root of Area) | Side Length |
|---|---|---|
| 144 square units | Square root of 144 | 12 units |
| 625 square units | Square root of 625 | 25 units |
| 900 square units | Square root of 900 | 30 units |
Section 5: Challenge and Extension
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a) Side Length: 32 inches (32 x 32 = 1,024) b) Perimeter Calculation: 32 + 32 + 32 + 32 or 4 x 32. Perimeter: 128 inches
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X = 324 (18 x 18 = 324)