On the original Macintosh Numeric Keypad, the keys ENTER, comma, plus, and
minus do not seem to correspond with the keys on the Calculator desk accessory.
However, although the keycap graphics do not match the Calculator keys, there
is a calculator function for each keycap. For instance, the ENTER key on the
keypad corresponds to the plus key on the Calculator. So, if your fingers are
accustomed to a 10-key numeric keypad, you can use the Macintosh keypad and
look at the screen and not the keys. Otherwise, please bear in mind the
differences between the keys on the Calculator and those printed on the
keycaps.