In mathematics, "∵" (upper two points, next point) stands for because, "∴" (upper two points, next two points) stands for why. The symbolic origin of mathematics because of harmony. But Ryan was the first person to express "so" with symbols. In an algebra book of 1659, he used two symbols "∴" and "⊙" to express "so", among which "∴" was used more.

These symbols are widely used in mathematics, science and engineering. There are also operation symbols in mathematics: plus sign (+), minus sign (-), multiplication sign (× or), division sign (÷ or/), union of two sets (∩), intersection (∩), root sign (√) and logarithm (log, lg, ln).