There are Greek letters in the soft keyboard of Chinese input method. Mathematical symbols can be entered by formula editor or MathType. Sei horse symbols are ∑ and ∑.

Sigma (capital σ, lowercase σ) is the18th Greek letter. In Greek, if the last letter of a word is lowercase sigma, it should be written in lowercase sigma. In modern Greece, this number stands for 6.

Capital σ is used for: mathematical summation symbol.

Lowercase σ is used for: a valence bond in chemistry, σ bond; Mechanical stress; Statistical standard deviation.

Both the с of Cyrillic alphabet and the S of Latin alphabet are derived from Sigma.