I got a new calculator last night, courtesy of my daughter.

She discovered she isn’t allowed to use a graphing calculator in her engineering class during exams, so she needed a “dumber” one in a hurry. She ordered the exact model she wanted—a purple TI-30XIIS—from Amazon. Then she started worrying it wouldn’t arrive in time, so she walked over to the campus store and bought a TI-30XS as insurance.

Between her TI-84 graphing calculator, the TI-30XIIS that arrived from Amazon on time, and the TI-30XS from the campus store, she found herself with three TI calculators—one more than she needed.

Which is how I finally crossed over to the Dark Side.

She’s always been a TI person, while I’ve been an HP person for decades, so we’ve had a friendly HP-versus-TI rivalry going in our house.

I can use a conventional calculator if I have to, but RPN logic—Reverse Polish Notation—just makes sense to me. My faithful HP-48GX has been with me through a lot of engineering over the years.

But I have to admit… it’s become overkill for my needs these days. It’s also a little slow by modern standards.

So I asked if I could adopt the larger of the two: the definitely-not-purple TI-30XS.

My HP-48GX isn’t going anywhere. It still has its place of honor. But I’m not solving systems of equations or calculating aircraft stresses anymore. For quick calculations, I suppose I can live with a TI on my desk.