How this project works
This project walks you through MiniCalc, a four-function calculator that runs entirely in the browser. You will not install Node, React, or any build tools. Each lesson adds one layer—structure, look, behavior, then polish—so you always know why a file exists.
You should already recognize basic HTML tags such as headings, paragraphs, and links. You do not need prior JavaScript experience beyond curiosity. When we introduce variables, events, and the DOM, we explain them in plain language before showing code.
Clone fcc-js-calculator. The repository has numbered folders. Each folder is a complete snapshot of the app at that stage. Open a folder with a local server, click around, then read the matching lesson to understand what changed.
By the end you will have digit entry, addition, subtraction, multiplication, division, clear, backspace, keyboard shortcuts, screen-reader labels, and a friendly message when someone divides by zero. Those pieces are the same ideas behind many interactive web pages.
Work in order from Part 1 through Part 4. Skip ahead only if a later snapshot already matches what you want to study. When something breaks, compare your files to the snapshot for that part rather than guessing.
Parts in order
Work through the parts in sequence. Each lesson explains the ideas, then points you to a runnable GitHub snapshot.