Using the Electronic Calculator. Fundamentals. Fractions. Base, Rate, and Portion. Checking Accounts and Check Reconciliation. trade and Cash Discounts. Payroll. Markup and Markdown. Sales and Propriety Taxes. Simple Interest. Discounting Notes, Compound Interest and Present Value. Using Credit. Depreciation/Overhead. Insurance - Life, Homeowners and Automobile. Stocks and Bonds. R.J. Marshall Wholesale/Retail Sporting Goods Case Problem.