Science & Tech

# Your Facebook friends have probably been sharing this graphic, but here's why it's wrong

This image, which claims to show the origins of our numerical system, has been widely shared on social media in the past week.

The graphic claims "our present method of writing figures is based on an early Arabic geometric design..."

"Where each figure contains its own number of corners or angles, for instance the first contains one angle, the third has three angles, the seventh has seven angles and so on."

It shows primitive-looking versions of our current numbers with a seemingly obvious explanation of why they are the shape they are.

But like all things on the internet - if it seems too good to be true, it probably is.

Professor Jeremy Gray, a British mathematician who specialises in the history of the subject, told i100.co.uk: "Itâ€™s nonsense."

Some clues in the original image give it away. Firstly, it seems unlikely that anyone would add on those extra lines on the extremely loopy 9, and as one commenter on Snopes, the debunking website, points out: "And the 5. It just keeps spiralling until 'Wheyhey! Prophecy fulfilled'."

And as Prof Gray points out, the numbers in the viral graphic are all rectangular, as opposed to the cursive typography that features in early Arabic and Brahmic script.

It also looks like itâ€™s the sort of thing youâ€™d carve on stone, not write on parchment, and frankly itâ€™s ugly.

• Prof Gray

The origin of our numbers is actually far more complicated. The Hindu-Arabic system that we know and recognise today (0, 1, 2, 3, 4, 5, 6, 7, 8, 9) was derived from Indian mathematics, as Gizmodo points out.

The Bakhshali manuscript, a snippet of which can be seen above, shows some of the early examples of algorithms as well as the early forms of the numbers we use today.

The figures from that manuscript, the oldest surviving document in Indian mathematics, then evolved through the centuries and were slowly adopted across the Middle East, North Africa and Europe. The first known use of them on the continent was displayed in the Codex Vigilanus - from 9th or 10th century Spain which was then under Arab rule.

A more likely evolution of the number system can be found in this graphic from the Open University, shared by Prof Gray:

The numbers were further developed throughout the second millennium AD and are thought to have taken their final form with influence from European typography styles.

Iâ€™d guess that this is one of those â€˜neatâ€™ ideas that people dream up on holiday when they canâ€™t be bothered to work. Thereâ€™s one chance in a hundred it was invented by the author of a boysâ€™ detective story â€“ 'Gosh, chaps, it all depends on counting the angles!'.

• Prof Jeremy Gray