EC-456 Dual-Powered Calculator (650-0898) Features Faxback Doc. # 18419 The Radio Shack EC-456 Dual-Powered Calculator can operate from two different power sources so you can use it almost anywhere. The calculator's built-in solar panel provides power when you expose the calculator to light. When there is not enough light, the supplied internal battery provides power. It's features include: Eight Large Digits - make calculations easy to read. Four Function Memory - saves important subtotals. +/- Key - changes the sign of the displayed number. Square Root Function - calculates the square root of the displayed number. Percentage Function - calculates add-on and discount percentages. Markup Function - helps you quickly determine a selling price based on a given cost and the desired gross profit margin, and calculate the gross profit margin with a given cost and selling price. Automatic Shut-Off - conserves battery power by turning off the calculator about 6 minutes after the last entry. (CD 11/2/95)