Matt and Janet suggested we build the calculator using software from ESPlanner, created by Boston University Professor of Economics Laurence Kotlikoff.

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When Paul was in high school he and his dad worked together to write encryption software for a calculator.

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If you are thinking about marriage late in life, get out your calculator, law books and tax software.

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But here we are months into the iPhone 5's existence and my 4 is still trudging along crankily as software updates conspire to remind me that it's an aging calculator bestowed upon me by the ancients.

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Users can intuitively operate the calculator using the stylus on the touch-panel LCD, and input data using the software keyboard.

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