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Everything I built
Variable Speed screenshot

Education

Variable Speed

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I wanted algebra practice you’d actually play again. Variable Speed breaks algebra into small moves, each one a chip on a circuit board. Get fast at the small ones and the equations they add up to get easy.

Screenshots

What it does

  • Each chip is one move, like calling the sign of −7 + 4 or knowing what undoes 3x. Bronze on a chip powers up the chips wired below it.
  • In Play, every problem falls toward your core. Answer before it lands. You get five shields, and each miss uses one.
  • Every right answer gets a rating, from GOOD up to LIGHTSPEED, and the music builds as your streak grows.
  • Warm up first if you like: one problem at a time, with the rule and a worked example after every miss.
  • Bronze, Silver and Gold on every chip, a ghost of your best run to race, and it all stays in your browser.

Built with

  • Vanilla JavaScript
  • Canvas 2D
  • Web Audio API
  • Playwright

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I write up builds like this one. What I did, what went wrong, and what is worth copying.

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