Create A Prototype Customized Calculator Device

I would like a prototype of a Calculating device. that would include special buttons (in addition to the regular standard calculator buttons) to calculate specific calculations. in addition, the device should include a memory capacity, to memorize/display previous calculation, as described below. **Basic Device design:** Similar to the small pocket calculators. **specific calculation buttons** ** 1. "Income**" this button would summarize total of the income. (for i.e. if i press 200 + "income" button, then it should add 200 to the income figure, [to the total of "income"]. **2. "expense"** This button will summarize all Expenses, (for i.e. i press 20 +" Expense" button, it will add the 20 to the total Expenses). **3. "Totals"** This button will display totals, of both, total income, and total expenses. ** 4. Up & Down Buttons & Delete** In order to move up and down to view the specific calculations... and edit/delete it. ------ I will give more Specifics/Purpose to chosen bidder. ------ Please serious Bidders Only