A mathematical symbol. In long division problems, the symbol looks like this:

)¯¯¯

This symbol has no actual name, although it is used in math textbooks throughout the US, and possibly all over the world.

Originally, the symbol was merely a closing parenthesis. ) One of the earliest known examples for this is found in Arithmetica integra by Micheal Stifel.

In the 1882 text Complete Graded Arithmetic by James B. Thompson, the use of the parenthesis is continued with the placement of a vinculum, or ____ below the dividend and then the quotient beneath that for examples of short division. In Robinson's Complete Arithmetic by Daniel W. Fish publised in 1901, the vinculum is attached to the closing parenthesis.

An early use of the modern symbol is in The Elements of Algebra by G. A. Wentworth, in 1888.

As the vinculum separated the dividend and quotient, it is likely that the change in position of the quotient caused the change in placement of the vinculum. I suspect that the quotient was moved to above to allow for the subtraction from the dividend when finding the solution.

Other symbols used in division are the obelus and the colon.