#### sum (summation)

• General syntax for symbols with a kind of lower and upper limits:

\symbolname_{lowerexpression}^{upperexpression}

• In general, there are two ways how these lower and upper expressions can be placed: centered below and above the symbol or in a subscript / superscript manner. In the first case the symbol name is preceded by the word "big", in the second there is no prefix.
• Syntax for summation symbol:

$$\bigsum_{i=k}^{n}gives \bigsum_{i=k}^{n} and \sum_{i=k}^{n}  gives $\sum_{i=k}^{n}$ • Use font size commands for a nicer picture:$$\LARGE\bigsum_{\small{i=1}}^{\small{n}}gives

\LARGE\bigsum_{\small{i=1}}^{\small{n}}

and

\large\sum_{\small{i=1}}^{\small{n}}

\$   gives

$\large\sum_{\small{i=1}}^{\small{n}}$