## Numerical Data and VariablesEdit

The most commonly used and necessary type of variable is the basic letter variable. The available characters are A-Z, θ (theta), and η (eta). On the TI-8x models these are the only types of numeric variables, leaving programming options limited to 28 defined areas in which to store variables in the calculator's memory.

This variable type is a double long, meaning that it stores data to the 9th decimal place.

This type will only store numerical data. Whether the input is an expression (2+3) or a single number (2.3535), the variable will only hold a single value (such as 5 or 2.3535).

To be added soon:The calculator treats real and complex values as different data types; these can be readily converted. Note that adding a single complex value to a list converts the entire list to complex, which can dramatically increase its size.