This calculator focuses on calulation involving percentages: markup, margin, percent change, percent of total and plus tax ("+ tax"). It also has a "M+" key for adding a list of values that you can review of edit with the List Manager.
Calculation Methods Used by CALC 1 for an overview of calculation methods.
Markup and Margin Examples for how to use the MU, COST, PRICE and MAR keys.
Percentage Change and Percent of Total Example for how to use the OLD, NEW, %CHG, TOTAL, PART and %TOT keys.