11
Correcting an Expression
This section explains how to correct an expression as you are 
inputting it. The procedure you should use depends on 
whether you have insert or overwrite selected as the input 
mode.
About Insert and Overwrite Input Modes
In insert mode, the displayed characters shift to the left to 
make room when your input replaces the character at the 
current cursor position. The initial default input mode is insert. 
You can change to overwrite mode as needed.
• The cursor is a vertical flashing line ( ❙ ) when insert mode 
is selected. The cursor is a horizontal flashing line ( 
_ ) 
when overwrite mode is selected.
• The initial default for Linear format input is insert mode. 
You can switch to overwrite mode by pressing 
  
(INS) 
• In Math format, you can only use insert mode. Pressing 
  (INS) when Math format is selected does not 
switch to overwrite mode. See “Incorporating a Value into 
a Function” for more information.
• The calculator automatically changes to insert mode 
whenever you change the input/output format from Linear 
to Math.
Changing the Character or Function You 
Just Input 
Example: To correct the expression 369 ✕ 13 so it becomes 
369 ✕ 12.