Smartphones have replaced a desktop calculator for most folks these days, but sometimes that tactility is just what you need to get the mathematical juices flowing. Why not spruce up the ...

HP famously built the first portable scientific calculator, the HP-35, although its reverse-Polish notation (RPN) might be a bit of a head-scratcher to those of us who came up in the TI world of ...

For example, A(B+C) would be expressed as * A + B C. In reverse Polish notation, it would be A B C + *. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction requires permission.