12 Digits, 150 Steps Check and Correct CalculatorOn Display Indication of Active Constant (K): Easier technique for repeat Calculation for +, -, ÷, x .Benefits: reduces any chances of manual error in repeat calculations.E.g. Press [2] [X] [X] (K is shown on screen) to set Multiply by 2 as constant. Enter, 10, and keep pressing [=] to get 20,40, 80, and so on.Dedicated GT key for Grand Total CalculationMark-Up: All the mark-up capabilities of an adding machine for simplified cost and profit calculations