The number 9 squared is equal to:

Squaring a number involves multiplying it by itself. In this case, when you take the number 9 and square it, you perform the calculation 9 multiplied by 9.

This results in 81, demonstrating that the value of 9 squared is indeed 81. This mathematical operation is fundamental to understanding exponents and is frequently used in various applications, including in physics and engineering contexts related to X-ray machines.

Understanding this concept reinforces the importance of basic arithmetic operations, which are crucial for precise calculations in different fields, including medical imaging.