Which electronic device best describes you? Shen Lik-hang, 16, Sing Yin Secondary School: The sigma symbol (Σ), which is generally used to denote a sum of multiple terms. My family comprises four ...

The uppercase use of sigma denotes a summation while the lowercase represents a measure of variation. Below are the uppercase and lowercase symbols for sigma: When used in the uppercase ...

Sigma is also updating its symbol, giving it a "contemporary update." The company says its new way of writing the Greek letter sigma – used in math to notate a summation – is meant to ...