What is the proper name for the \div symbol used in mathematics to indicate division?
The proper name for the \div symbol used in mathematics is the obelus. It consists of a horizontal line with a dot above and a dot below, and it has been used to represent division since the mid-17th century.
Quick Definition:
The obelus (\div) is a mathematical glyph traditionally used to signify the operation of division. While common in elementary education and on handheld calculators, it is less frequent in advanced mathematics, where the solidus (forward slash /) or fraction bar is preferred.
Table of Contents
The History of the Obelus
The term obelus comes from the Greek word obelos, meaning a sharpened stick, spit, or pointed pillar. Historically, the symbol was used by ancient grammarians to mark passages in manuscripts that were suspected of being corrupted or spurious.
It was first introduced as a symbol for division in 1659 by the Swiss mathematician Johann Rahn in his book Teutsche Algebra. Shortly after, it was adopted by English mathematicians like John Pell, which helped solidify its place in the English-speaking world as the primary division sign.
Alternative Division Symbols
In mathematics, division can be represented in several ways depending on the context and the complexity of the expression:
- The Solidus (/): Also known as the forward slash, it is the standard for inline equations and computer programming (e.g., 10 / 2 = 5).
- The Fraction Bar (—): Used in vertical notation where the dividend is the numerator and the divisor is the denominator.
- The Colon (:): Common in European and Turkish mathematics (YKS/TYT) to denote division or ratios (e.g., a : b).
Pro Tip: In advanced algebra and calculus, the obelus is rarely used because it can lead to ambiguity in long strings of operations. Scientists and engineers almost exclusively use fraction bars or the solidus.
Usage in Modern Mathematics
Today, the obelus remains a staple in primary school education because it clearly distinguishes division from other operations for young learners. It is also the universal symbol for the division key on most electronic calculators.
However, students preparing for exams like TYT or YKS should be comfortable seeing division represented by a colon (:) or a fraction, as these are the formats most likely to appear in advanced test booklets.
Summary Table
| Feature | Details |
|---|---|
| Primary Name | Obelus |
| Origin | Ancient Greek (obelos) |
| First Math Use | 1659 (Johann Rahn) |
| Common Uses | Primary school, calculators |
| Preferred Alternatives | Solidus (/), Fraction Bar, Colon (:) |
Next Steps
Shall I explain the specific rules for the order of operations (PEMDAS/BODMAS) when using division symbols in complex equations?