Such as plus sign (+), minus sign (-), multiplication sign (× or), division sign (÷ or/), union of two sets (∩), intersection (∩), root sign (√), logarithm (log, lg, ln) and ratio (:).

Relational character

For example, "=" is an equal sign, "≈" is an approximate sign, "≦" is an equal sign and ">" is a greater than sign. "