EC-215 Sales Tax Calculator (650-0573) Features Faxback Doc. # 19158 Your Radio Shack EC-215 Sales Tax Calculator has two different power sources so you can use it almost anywhere. Its built-in solar panel provides power when you expose the calculator to light. In low light, the supplied internal battery automatically powers the calculator. The EC-215's programmable tax rate function is great for calculating sales taxes, tips, and more. Its other features include: Three-Function Memory - lets you save, add to or subtract from, and recall subtotals. % Key - simplifies calculating discounts, percentages, and tax amounts. Square Root Function - lets you quickly compute the square root of a number. +/- Key - lets you change the sign of the displayed value. Automatic Shut-Off - conserves battery power by automatically turning off the calculator about 6 minutes after the last entry. (PH 10/05/95)