To express 64 as a fraction in simplest form, we can represent it as 64/1. This is because any whole number can be written as a fraction by placing it over 1.
Next, we need to check if 64/1 can be simplified further. In this case, 64 is already in its simplest form since the only common factor between 64 (the numerator) and 1 (the denominator) is 1.
Thus, the fraction 64/1 represents the whole number 64, and since there are no further simplifications possible, 64 as a fraction in simplest form is 64/1.