for parents, teachers and curious kids
Halve a string and it sings an octave higher. Add note lengths until they make exactly one, and you have a bar of music. Every idea a child meets in maths and science class — fractions, ratios, times tables, waves, even logarithms — is already living inside an instrument, waiting to be pressed.
Atlas is a free set of rooms where those ideas make a sound. Nothing to install, nothing to sign up for, no score to chase and no quiz to fail. A child taps something, hears what it does, and the number underneath stops being homework and starts being the reason it sounded like that.
Roughly ages 9 to 14. That is the age when fractions, ratios and waves all arrive at once — and the age when a thing you can hear beats a thing you must memorise.
Under each room there is a Go deeper panel with the real mathematics: logarithms, geometric sequences, exponential decay. Plenty here for grades 9–12 and for a curious adult.
Every instrument on the site is playable in the browser, with real recorded sound. You do not need to own one, read music, or have had a single lesson to start.
what you'll learn, and where
Pick whatever your child is doing at school this term — or whatever simply sounds interesting — and follow it straight to the room where you can play it. The grade bands are a guide, not a gate: younger children happily play with the later rooms, and older ones still enjoy the early ones.
The number work every primary and middle-school class does — except here you hear the answer instead of marking it right or wrong.
Circles, lengths and areas you can hit, pluck and pace out across the room.
Why some patterns come back round to where they started and others never quite do. Puzzling, and completely hearable.
A whole physics topic proved out loud, in an ordinary room, with no lab equipment at all.
Randomness turns out to have a sound, and it is the snare drum.
For students who have started algebra: relationships that do something audible the moment you change a number.
The multiplying world — and the trick musicians invented, centuries before mathematicians named it, for turning × into +.
or come in the other door
Each one has a beginner's path, a playable version you can use right now, a listening room, and a science room where the numbers behind it come out.
Twelve notes, and why there are twelve.
Six strings and a ruler that shrinks.
Three valves counting in binary.
The one instrument with no notes — just a slide.
Waves long enough to walk along.
A drum with strings on it.
Rhythm, randomness and metal that rings.
The instrument you were born holding.
if you teach
Teachers are very welcome here, and the rooms were built with a lesson in mind. Most of them close with a For the classroom card: the learning goals written in syllabus language, plus two things you can actually do with a class. Everything runs in a browser on whatever is already in the room — and if you can bring the real instrument along, better still. The app is the blackboard; the instrument is the proof.
Open the Math Lab and slide a bridge along a string, or pick up an instrument and play it in the browser. And if you would like us to bring all of this into your school for a morning — real instruments, a real room full of children — we would love to.