/// Calculate width for a default column
///
/// @author [@esr360](http://twitter.com/esr360)
/// @access public
/// @group Kayzen-GS
/// @param {number} $span - the width (in columns) of returned value
/// @param {number} $columns - the maxinum number of columns being used
/// @return {number} - width of column
@function kgs-default-width($span, $columns) {
    @return ((100 / $columns) * $span) - ( ( ((100 / ((100 / $columns) * $span)) - 1) * kgs-option(gutter) ) / ( $columns / $span ) );
}