HP 35s Scientific Calculator - Manual (Page 237)

Solving and Integrating Programs 15-3
To begin, put the calculator in Program mode; if necessary, position the program
pointer to the top of program memory.
Type in the program:
Press  to cancel Program–entry mode.
Use program "G" to solve for the pressure of 0.005 moles of carbon dioxide in a
2–liter bottle at 24 °C.
Keys:
(In ALG mode)
Display: Description:
 
   
Sets Program mode.
Program Lines:
(In ALG mode)
Description:
   Identifies the programmed function.
   Stores P for pressure
   Stores V for volume
   Stores N for number of moles of gas
   Stores R for gas constant
   Stores T for temp.
  ЧЧЧ Press 
Pressure × volume = Moles × gas constant × temp.
  Ends the program.
Checksum and length: F425 33
Keys:
(In ALG mode)
Display: Description:
G
Selects "G" — the program.
SOLVE evaluates to find the value
of the unknown variable.
P 
value
Selects P; prompts for V.
 
value
Stores 2 in V; prompts for N.