Rob Pike's Secret Calculator: Ivy

Standard calculators choke on huge numbers, and Python is overkill for quick terminal math. Enter Ivy. It’s a bignum calculator and APL-style interpreter written in Go. It handles infinite precision math, floating points, text, and custom operators. Instead of verbose code, you get insanely concise array-based logic. It’s the perfect playground to explore array processing and heavy mathematics. It even has iOS and Android apps!