HP (Hewlett-Packard) 35s ユーザーズマニュアル

Among the first things you need to know are how to clear an entry, correct a 
number, and clear the entire display to start over.



Backspace. 
If an expression is in the process of being entered, 



 erases the 

character to the left of the entry cursor ( _ ).  Otherwise, with a 
completed expression or the result of a calculation in line 2, 



 

replaces that result with a zero. 



 also clears error messages 

and exits menus. 



 behaves similarly when the calculator is in 

program-entry and equation-entry modes, as discussed below:

Equation–entry mode:
If an equation is in the process of being entered or edited, 



 erases the character immediately to the left of the insert 

cursor; otherwise, if the equation has been entered (no insert 
cursor present), 



 deletes the entire equation.

Program-entry mode:
If a program line is in the process of being entered or 
edited, 



 erases the character to the left of the insert 

cursor; otherwise, if the program line has been entered, 



 

deletes the entire line.



Clear or Cancel. 
Clears the displayed number to zero or cancels the current 
situation (such as a menu, a message, a prompt, a catalog, or 
Equation–entry or Program–entry mode).