On most HP calculators model that has dual mode, the algebraic annunciators and keys are labeled as ALG.
This is the name of the mathematic notation used on all non-RPN calculators where you enter a mathematic equation like this: 1+3*(3+(2-5)/3). In algebraic mode, parentheses and order of operations are extremely important.
The algebraic mode of operation uses the following hierarchy:
1. Parentheses
2. Exponents
3. Multiplication and Division
4. Addition and Subtraction