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no historical likeness exists

476 – 550Kusumapura, India

Aryabhata

A digit's value depends on its place: the foundation of every later number system.

A short story

An Indian astronomer who, fifteen hundred years ago, wrote down the way numbers really fit together: a digit's value depends on its place. He used decimal place value to compute the size of the year, the speed of planets, the diameter of the Earth: work that needed numbers far larger than anyone in his world had names for.

In their own words

Ones, tens, hundreds, thousands, ten-thousands: each place ten times the place to its right.

Paraphrased: from Aryabhata's Āryabhaṭīya, 499 CE, on the writing of numbers.

The lab their idea turned into

Tower Lab

Each block sits in a place. Where it sits decides what it's worth.

Open Tower Lab