Stuff You Should Know – Short Stuff: Origin of Math Signs

Intro

In this episode of the “Stuff You Should Know” podcast, the hosts delve into the fascinating origins of math symbols. They explore the history behind the plus, minus, multiplication, division, and equal signs, revealing how these symbols revolutionized the way math problems were written and taught.

Main Takeaways

Evolution of Math Symbols

• Before symbols, math problems were written out as long word problems.
• The symbols saved time and made writing and teaching math easier.
• Some people wrote math problems in diverse metered verse, like poems, which was time-consuming and unnecessary.

Origin of Equal Sign

• Robert Record, a mathematician and physician, proposed the equal sign because it consists of two parallel equal lines.
• He introduced it as a time-saving shorthand for “is equal to”.

Plus and Minus Symbols

• The plus and minus symbols come from Latin, with plus meaning “more” and minus meaning “less”.
• The plus symbol originally comes from the Latin word “et”, meaning “and”.
• It was first used as a shorthand for “et” by a French philosopher named Nicole Oresme in the 14th century.
• Luca Patioli used the symbol P with a line over it for plus and M with a line over it for minus, which eventually became the minus sign.

Multiplication Symbol

• The multiplication symbol is not an x, it’s called the cross of San Andreas.
• X already represents something in math, so it’s incorrect to say the multiplication symbol is a little x.
• William Autred introduced the multiplication symbol in the 1630s.
• The cross of San Andreas was first used in a translation of a book of logarithms from 1618, but the anonymous author is unknown.

Division Symbol

• The division symbol is officially called an obelis and is supposed to represent a small dagger.
• Johann Ron from Switzerland started using the obelis in 1659.
• The backslash symbol for division is called a fraction bar or a solidus.
• The ISO says that only the solidus or fraction bar should be used to indicate division, not the obelis.

Apologies and Conclusion

• The hosts admit they were misled and apologize for any confusion.
• They express interest in learning the correct symbol and encourage listeners to write in.
• The “Short Stuff” podcast is ending, and it is produced by iHeartRadio.
• For more podcasts, visit the iHeartRadio app or Apple podcasts.

Summary

The Evolution of Math Symbols

Before the introduction of math symbols, math problems were written out as lengthy word problems, making the process time-consuming and cumbersome. However, the adoption of symbols revolutionized the way math was written and taught, saving time and simplifying the process. Some individuals even resorted to writing math problems in metered verse, akin to poetry, which added unnecessary complexity.

The Origin of Equal Sign

Mathematician and physician Robert Record proposed the equal sign as a time-saving shorthand for “is equal to”. The symbol consists of two parallel equal lines, making it visually representative of equality. This simple yet powerful symbol transformed the way equations were written and understood.

The Plus and Minus Symbols

The plus and minus symbols have their roots in Latin. The plus symbol, originally derived from the Latin word “et” meaning “and”, was first used by French philosopher Nicole Oresme in the 14th century as a shorthand for “et”. Luca Patioli later introduced the symbols P with a line over it for plus and M with a line over it for minus, which eventually evolved into the familiar plus and minus signs we use today.

The Multiplication Symbol

Contrary to popular belief, the multiplication symbol is not a little x. It is known as the cross of San Andreas. William Autred introduced this symbol in the 1630s, but its origin can be traced back to a translation of a book of logarithms from 1618, where an anonymous author first utilized the cross of San Andreas.

The Division Symbol

The division symbol, officially called an obelis, was intended to represent a small dagger. Johann Ron from Switzerland started using the obelis in 1659. However, the ISO recommends using the solidus or fraction bar as the appropriate symbol for division, rather than the obelis. Attempts have been made to introduce alternative division symbols, such as “Alt, two, four, six”, but these have not gained widespread acceptance.

Conclusion

The origins of math symbols reveal the ingenuity and creativity of mathematicians throughout history. From the introduction of time-saving shorthand to the visual representation of mathematical concepts, these symbols have shaped the way we understand and communicate math. As the “Short Stuff” podcast comes to a close, the hosts express their curiosity in learning more about the correct usage of symbols and encourage listeners to engage in the ongoing exploration of mathematical language.