Canon P20-DX User Manual page 5

Power On/Paper Feed Key: Used to feed the paper when the power switch is
on, and also used to reactivate the display if the Automatic Power Off Function
(see p.6) turns the calculator off.
Decimal Point Selector Switch: For designating the decimal point position for
calculation results.
F (Floating Decimal Point): All effective numbers up to 10 digits are printed or
displayed.
+ (Add-Mode): Addition and subtraction are performed with an automatic
2-digit decimal. The "+" key need not be depressed for individual entries.
Power and Printer Switch: This switch is used to turn the power on and off
and also to turn the print function on and off. Slide the switch to the center
position to turn the power on. Setting the switch at the leftmost position turns the
print function on.
5