Bruce Sherwood, the co-author of Matter and Interactions, had a question for me when I saw him at the American Association of Physics Teachers conference not long ago: "What calculator do you use?"

If this seems odd, well, it was a conference of physics teachers. I responded with something along the lines of "I don't actually use a calculator." Of course, Bruce probably knew I'd say that. He absolutely agrees with me.

I don't remember the last time I use a traditional calculator. When students ask to borrow one, I show them this:

Rhett Allain

Yes, that is a classic HP 11C from the 1980s. It cost $135 back then—a fortune. It's still a great calculator, but I'm not about to let a student borrow it. Not because I'm mean, but because older scientific calculators use RPN and I doubt many students know RPN. Now, you may ask, "Why don't you have a modern calculator, Rhett?" I have many reasons, not the least of which is I never use a calculator. I'd bet most scientists don't use a calculator.

Neither should you.

So how do I calculate stuff? A slide rule? No. Although slide rules are cool, most scientists don't use those, either. For simple things like finding a square root or converting, say, Fahrenheit to Celcius, I use a web browser. You can just type stuff right into the Google search box. Try it. Type "sqrt(4.55) meters in feet." Not only does Google determine the answer, it converts it from meters to feet (although I have no idea why you would want to do that).

For longer calculations, I use the programming language Python, usually a web-based version like you find at trinket.io. Let me show you how with a fairly typical introductory physics problem.