Editor’s note: Also see Ken Coffman’s blog: The HP15C returns as an iPhone app. With the emergence of hand-sized computers, calculators have lost some of their former prominence, yet they continue to ...

The app's intuitive user interface allows easy insertion of units for quick solutions of even the most complex calculations. The units of measure that these engineering calculators cover include ...

Mechanical calculators are an engineering marvel unknown to most people. The most advanced mechanical calculator ever built, the Curta calculator, fits into the palm of your hand and uses dozens of ...