Here’s something interesting that popped up in my inbox today. Ever notice that the number of angles less than 180˚ in each of our Arabic number symbols corresponds to the number the symbol represents? It’s an interesting take on the origin of the Arabic numeral system … except that it’s not true.

My first hint was that for zero, “angle” was magically turned into “angel”. And why, exactly, do seven and nine need all that extra embellishment? Before you sound the sad trombone, why don’t we use this time to explore the real question: Where DO our numeral symbols come from?

For starters, Arabic numerals do not originate with the Arabs. Our numerical symbols actually trace their roots back to India at least as long ago as the 3rd century BC. These Brahmi numerals show obvious similarities with our modern “Arabic” symbols, as seen below (via Wikipedia):

The lack of a zero should not go unnoticed. Multiples of ten were given their own symbols in Brahmi, and large numbers were written as combinations of symbols instead of neat little decimals like we’re used to.

The idea of zero as a number (and not just numerical punctuation) makes its earliest appearance in the fifth century AD, again in India. Over time, the Indian numerical system migrated west into Persia, where decimal notation and the round 0 were formalized. In 976 AD, the Persian version of Wikipedia known as Muhammad al-Khwarizmi is credited with the invention of the word “sifr” to represent the empty decimal place, which later evolved into the very word we use for it today: zero.

From Persia, the “Arabic” symbols quickly made their way into Europe, along with their misattributed name. Like letter forms of the time, they were not standardized, and people wrote the symbols in their own style (which, to this day, is why some 2’s curl, and some 7’s are crossed).

With the development of moveable type, symbols were quickly standardized into the forms we know (and love?) today. Thanks, Gutenberg!

If you’re interested in more numerical history, check this out, or this. Numbers have a history with many interesting angles, but the geometric ones have nothing to do with why numbers look the way they do.