Determine the value of the given mathematical expression: $100^{-\frac{1}{2}}$

Step 1 ：The given expression is a power of a number. In this case, the number is 100 and the power is -1/2. The negative sign in the power indicates that we need to take the reciprocal of the number, and the 1/2 indicates that we need to take the square root. So, we need to calculate the square root of 100 and then take its reciprocal.

Step 2 ：Calculate the square root of 100: \( \sqrt{100} = 10.0 \)

Step 3 ：Take the reciprocal of 10.0: \( \frac{1}{10.0} = 0.1 \)

Step 4 ：Final Answer: The value of the given mathematical expression \(100^{-\frac{1}{2}}\) is \(\boxed{0.1}\)