Every student has faced a strange classroom rule that makes them question reality.

For one computer science major, it came when his professor insisted he ditch his calculator for a “less programmable” device… his smartphone.

Let’s just say the irony wasn’t lost on him.

You’ll want to keep reading for this one!

You can program your calculator, use your phone instead.

Short but funny story from college.

I was taking a science class back in my college days, and I had a TI-89-ish calculator for all my classes.

His teacher had a very puzzling rule.

My professor apparently had a rule where you couldn’t use scientific calculators — you could only use a basic one.

Well, on a test day, I brought in my regular TI calculator, and the professor came up to me saying I could program that and told me to use my phone instead.

This student couldn’t get over just how illogical this rule seemed.

The funny part? I was a software engineer (going for a computer science degree at the time) who probably could have figured out how to write a basic calculator app with anything I could have cheated with.

From then on, I just used my phone, knowing I could secretly cheat if I really wanted to — because apparently, you can program your TI, but not your phone.

This student couldn’t help but grin at the absurdity of it all.

What did Reddit think?

This user wonders what’s holding calculator innovation back so much.

Professors understand that real employees have access to tools like calculators, right?

Teachers don’t always like high performers.

Let’s take a moment of appreciation for calculators.

This student didn’t dare argue with the professor again.

Why fight the system when the loophole is smarter than the rule itself?

If you liked that post, check this one about a guy who got revenge on his condo by making his own Christmas light rules.