Perfect Squares and Square Roots Worksheets Square root means getting the number that was multiplied to get the number. For example: 3 squared is 9, so a square root of 9 is 3. 4 squared is 16, so the square root of 16 is 4. 5 squared is 25, so the square root of 25 is 5. The symbol of the square root is √, which is known as radical. Basic Lesson