Scientific Calculator

Okay. It's a calculator. On a game site. I know how that looks. But here's the thing. I kept using browser calculators for work, and they kept being wrong. Most of them use something called eval under the hood. That means they read your math like a sentence, left to right. 2+3×4? They say 20. The answer is 14. Multiplication comes first. This drove me crazy. So I wrote my own math reader from scratch. It's called a recursive-descent parser. That just means it understands the rules of math the way you learned them in school.

Then I kept going. Couldn't help it. Sine, cosine, tangent. Their inverses. Logarithms. Square roots. Cube roots. Powers. Factorials. Pi and e as one-click buttons. A switch between degrees and radians. Memory buttons that actually work. I told my wife I was building a calculator. She said she could count on that. At some point I looked up and I'd built a full scientific calculator. I was supposed to be doing laundry. The laundry did not get done.

The history panel is the part that made this actually useful. Every calculation gets saved. Click an old result and it drops back into what you're working on. There's an undo button that goes 50 steps deep. And a little counter that tells you how many open parentheses you have. That sounds small. It's not. When you're six parentheses deep in a nested expression, that counter is the only thing keeping you sane.

I care about how things look. Even a calculator. The display is LCD-style. Buttons are color-coded. Orange for math. Red for clear. Blue for equals. It feels like a real calculator. A good one. You can type everything on your keyboard too. Click the answer to copy it. I use this for real work now. It lives in a browser tab. It's the nerdiest thing on this site and I am extremely proud of it.