A Short History of Signs and Symbols

,    Paolo Dagomari (1281-1372), an Italian mathematician, first used 
     the comma to separate large figures into units of three. Comma
     sign was first used in text in England in 1534.

+    Plus sign was first used by John Widman in Leipzig, Germany in
     1489.

-    Minus sign was first used by John WWidman in Leipzig, Germany in
     1489.

!    Exclamation mark was first used by John Day, an English printer,
     in 1553.

=    Equals sign was first used by Robert Recorde, an English
     mathematician,  in 1557.

*    Asterisk sign was used by Sir Philip Sidney, an English poet,
     politician, and soldier in 1587.

?    Question mark was used by Sir Philip Sidney, an English poet,
     politician, and soldier in 1587.

>    Greater-than sign was first used by Thomas Harriot, an English
     astronomer, mathematician, and physicist,  in 1621.

<    Less-than sign was first used by Thomas Harriot, an English
     astronomer, mathematician, and physicist,  in 1621.

÷    Division sign was first used by John Pell, an English diplomat
     and mathematician, c.1630 and Johann Heinrich Rahn, a Swiss
     mathematician, in 1659.

x    Multiplication sign was first used by William Oughtred, an
     English mathematician, in 1631.

∞   Infinity symbol was first used by John Wallis, an English
     mathematician, in 1655.