\label{Spreadsheet_HowTo} \textbf{Summing up columns} To take the sum of column ``M'', for example, use \texttt{\&SUM(``M*'')}\index{SUM} \textbf{Spreadsheet Lists} When you have a list of numbers in a cell, how it is displayed depends on how you separate the numbers and how Perl interprets the results. \textbf{35 45 12} will not generate any result because this is an invalid Perl statement. \textbf{35,45,12} will have a result of 12 because Perl has a comma operator similar to the comma operator\index{comma operator} in C. The comma operator is binary and returns the value on its right. Thus \texttt{\$variable = 15, 26;} assigns \texttt{\$variable} the value 26. If you need the values to all be displayed, enclose the entire cell contents in quote marks.