If you have a storage device with a capacity of 16 gigabytes, how many 32 kilobyte files can you fit in that device? (1 KB = 1024 bytes)

Sixteen gigabytes equals two to the thirty-fourth bytes, as sixteen is two to the fourth and a gigabyte is two to the thirtieth.

A thirty-two kilobyte file equals two to the fifteenth bytes, since thirty-two is two to the fifth and a kilobyte two to the tenth.

Dividing capacity by file size subtracts exponents, thirty-four minus fifteen, yielding two to the nineteenth files.

Two to the eighteenth would result only from an eight-gigabyte device.

Two to the twentieth would need a larger store, and two to the fourteenth is far too few.

Subtracting exponents works only when both sizes are written as powers of two with the same base.