Pressing the "Esc" key is the same as clicking the "C" button.
Holding down the "Shift" key and then pressing the "~" key is the same as clicking the "+/-" button.
Holding down the "Shift" key and then pressing the "%" key is the same as clicking the "%" button.
Pressing the "/" key is the same as clicking the "/" button.
Pressing the "*" key is the same as clicking the "*" button.
Pressing the "-" key is the same as clicking the "-" button.
Pressing the "+" key is the same as clicking the "+" button.
Pressing either the "Enter" key or the "=" key is the same as clicking the "=" button.
Pressing the "." key is the same as clicking the "." button.
Pressing the "Backspace" key is the same as clicking the "⎌" button.
Pressing any number key is the same as clicking the matching number button.