Where the symbols came from
Almost every sign in a line of mathematics is younger than the printing press. Each one here sits at the year it first appeared. Hover or tap one to see who drew it, and what people wrote before.
Take them away
Drag the year back. Every sign that did not exist yet turns into what people wrote instead, and the formulas swell into sentences.
2000
Digits, brackets, fraction bars and letters are left as they are. Their histories are longer and murkier, and letters for numbers only arrive with Viète in 1591, so before that even the a, b and c are an anachronism. Dates follow Florian Cajori’s A History of Mathematical Notations and Jeff Miller’s Earliest Uses of Various Mathematical Symbols; “c.” marks a year that is only approximate.