Where Do Math Symbols Come From?

Ever since your first math class, you’ve been learning the meaning of symbols like = , +, – , x, and more. But those symbols haven't always existed; nor have they always meant what they do today. Centuries ago, mathematical symbols looked different depending on what language you spoke. In 1557, Robert Recorde of the United Kingdom wrote the first equal sign, which looked much like it does today. French mathematician René Descartes used a symbol that looked like this:∝. Gottfried Wilhelm Leibniz of Germany used a wedge shape.

The symbols we utilize today came about after much debate among mathematicians—and across cultures. Some historians believe that the printing press pushed people to use the same symbols, and by the 1700s most math symbols were standardized. “While many words have a variety of meanings, mathematical symbols strive to be as specific as possible,” says Peter Schumer, a professor of mathematics at Middlebury College in Vermont.

Yet like language, math symbols can still change. “Even our modern numbers, 1, 2, 3, 4, and so on evolved over many centuries and no doubt will continue to be modified to some extent,” Schumer adds. Read on to learn more about the origins of some math symbols we use—for now!

Ever since your first math class, you’ve been learning the meaning of symbols. These include = , +, – , x, and more. But those symbols haven't always existed. And they haven’t always meant what they do today. Centuries ago, mathematical symbols looked different depending on what language you spoke.

In 1557, Robert Recorde of the United Kingdom wrote the first equal sign. It looked much like the one we use today. But French mathematician René Descartes used a symbol that looked like this: ∝. Gottfried Wilhelm Leibniz of Germany used a wedge shape.

The symbols everyone uses today took a long time for mathematicians to agree on. Some historians believe that the printing press pushed people to use the same ones. By the 1700s, most math symbols were the same across languages and cultures. “While many words have a variety of meanings, mathematical symbols strive to be as specific as possible,” says Peter Schumer. He’s a math professor at Middlebury College in Vermont.

But math symbols can still change, just like language does. “Even our modern numbers, 1, 2, 3, 4, and so on, evolved over many centuries,” adds Schumer. “No doubt they will continue to be modified to some extent.” Read on to learn more about the origins of some math symbols we use—for now! 

Over the years, trade and shipping spread math symbols around the world. In fact, the plus and minus symbols we use for addition and subtraction may not have been used in equations at first! Instead, they were used to show a surplus (+) or deficit (–) of goods bought and sold.

Sailors spread these symbols as they traveled, recording what they carried using this shorthand. The 1489 book Mercantile Arithmetic by Johannes Widmann of Germany is one of the first instances of + and – signs in print. In his book, he describes the weight of goods as “4 centner + 5 pfunds,” where 1 centner is 100 pfunds. (Pfunds and centner are archaic units of weight.) How many pfunds is Widmann describing in this expression?

As traders traveled the world to sell goods, they also helped spread math symbols. In fact, the plus and minus symbols we use today got their start this way. They may not have been used for addition and subtraction equations at first. Instead, they were used to mark a surplus (+) or deficit (–) of goods being traded.

Sailors used this shorthand to record what they carried with them. A 1489 book is one of the first times + and – signs appeared in print. Johannes Widmann of Germany wrote the book, called Mercantile Arithmetic. It also includes old units of weight, like centner and pfunds, where 1 centner is 100 pfunds.  Widmann describes the weight of goods as “4 centner + 5 pfunds.” How many pfunds is Widmann describing in this expression?

The letter x is often used to represent an unknown amount. Scholars believe that the symbol arose in Arabic-speaking places, where the word al-shayun means “something.” It was shortened to just “sh,” a sound represented by the letter x in Spanish and Portuguese. It’s possible that the symbol x then spread from where people spoke those languages.

Other historians hypothesize that René Descartes of France used x for an unknown quantity because book printers had extras of that letter, since it's used infrequently. In the French language, x has a frequency of only 0.42%. How many of the letter x would you expect to be in a book written in French with a total of 330,000 letters?

The letter x is often used to represent an unknown amount. Scholars believe that the symbol arose in places where people spoke Arabic. The word al-shayun means “something” in Arabic. It was shortened to just “sh.” That sound is represented by the letter x in Spanish and Portuguese. It’s possible that the symbol x spread when those cultures interacted.

But there’s another theory too. Some historians think that René Descartes of France used x for an unknown quantity, because it doesn’t appear often in French. That meant book printers often had extras of that letter. In the French language, x has a frequency of only 0.42%. How many of the letter x would you expect to be in a book written in French with a total of 330,000 letters?

Ancient Arab culture is credited with creating a horizontal bar to show division. A book published in 1194 first used this symbol for division, like a fraction.

It wasn’t until 1659 that a Swiss mathematician named Johann Heinrich Rahn started using the division symbol we use today, called an obelus (÷). Ancient Greeks originally used the obelus to mark passages in manuscripts that were thought to be incorrect or doubtful.

But today people primarily use the obelus in math computation. What’s the ratio of the number of years the horizontal bar was used before the obelus became a math symbol to the number of years the obelus has been used as a math symbol?

Ancient Arab mathematicians didn’t just come up with x. They also started using a horizontal bar to show division. A book from 1194 first used this symbol. We still use it today to show division in a fraction.

The other main division symbol is called an obelus (÷). Swiss mathematician Johann Heinrich Rahn started using it in 1659. He didn’t invent the symbol. Ancient Greeks originally used the obelus to mark passages of writing they thought were incorrect.

But today people mostly use the obelus in math equations. What’s the ratio of the number of years the horizontal bar was used before the obelus became a math symbol to the number of years the obelus has been used as a math symbol?