Application Guide

154 Using Variables
Using a Variable in a Calculation
After storing a value in a variable, you can use the variable name in an expression as a
substitute for the stored value.
1. Enter the expression:
- Type 4*25*num^2 on the entry line, and press Enter.
- Handheld: Type 4 r 25 r num q on the entry line, and press ·.
Calculator substitutes 517, the value currently assigned to num, and evaluates the
expression.
2. Enter the expression:
- Type 4*25*nonum^2, and press Enter.
- Handheld: Type 4 r 25 r nonum q on the entry line, and press ·.
CAS: Because the variable nonum has not been defined, it is treated algebraically in
the result.
Because the variable nonum has not been defined, the expression returns an error
message.
Naming Variables
Variable and function names that you create must meet the following naming rules.
Note: In the unlikely event that you create a variable with the same name as one used
for statistical analysis or by the Finance Solver, an error condition could occur. If you
begin entering a variable name that is already in use in the current problem, the
software shows the entry in bold to let you know.
• Variable names must be in one of the forms xxx or xxx.yyy. The xxx part can have
1 to 16 characters. The yyy part, if used, can have 1 to 15 characters. If you use the
xxx.yyy form, both xxx and yyy are required; you cannot start or end a variable
name with a period “.”.