To evaluate the expression \( 6.9 - 2^0 \), we first need to calculate \( 2^0 \).
Any non-zero number raised to the power of zero is equal to 1. Therefore,
\[ 2^0 = 1 \]
Now we can substitute that back into the original expression:
\[ 6.9 - 2^0 = 6.9 - 1 \]
Performing the subtraction:
\[ 6.9 - 1 = 5.9 \]
Thus, the value of \( 6.9 - 2^0 \) is \( 5.9 \).
So the answer is:
5.9