HP 35s Scientific Operator Precedence, How operators interact, What functions are valid in equations, 6-14 Entering and Evaluating Equations

To change the number, type the new number and press . This new number writes over the old value in the X–register. You can enter a number as a fraction if you want. If you need to calculate a number, use normal keyboard calculations, then press . For example, you can press 2

5 in RPN mode, or press 25 in ALG mode. Before pressing , the expression will display in line 2, and after pressing , the result of the expression will display in line 2.

To cancel the prompt, press . The current value for the variable remains in the X–register and displays in right-side of the line two. If you press  during digit entry, it clears the number to zero. Press again to cancel the prompt.

To display digits hidden by the prompt, press .

In RPN mode,each prompt puts the variable value in the X–register and disables stack lift. If you type a number at the prompt, it replaces the value in the X–register. When you press , stack lift is enabled, so the value is saved on the stack.

The Syntax of Equations

Equations follow certain conventions that determine how they're evaluated:How operators interact.What functions are valid in equations.How equations are checked for syntax errors.Operator Precedence

Operators in an equation are processed in a certain order that makes the evaluation logical and predictable:

6-14Entering and Evaluating Equations