Calculate a Triangle Number — CodeCodex Math The sum of the first n integers, the shape that gives it its name, and the one-line formula that replaces an entire loop. Difficulty: Beginner Languages: Python · JavaScript · Pascal Read: ~8 min In this article What a triangle number is, visually and numerically The loop-based approach…

Calculate the Factorial of a Number — CodeCodex Math The first recursive function most programmers ever write — and the one that quietly teaches stack limits, big-integer arithmetic, and why iteration sometimes wins. Difficulty: Beginner Languages: Python · C · Haskell Read: ~9 min In this article What a factorial is, and where it comes…

Calculate an Integer Square Root — CodeCodex Math Finding ⌊√n⌋ without floating point — three approaches, from the naive crawl to the one fast enough to belong in a hot loop. Difficulty: Beginner–Intermediate Languages: C · Python · Java Read: ~9 min In this article What an integer square root actually is The naive approach:…