Don't add values that have been formatted using number_format(), otherwise they may well contain , as a thousand's separator... they're treated as strings rather than floats.
Assuming that $cash, $card and $check are arrays:
$cash = array_sum($cash); $card = array_sum($card); $check = array_sum($check); $total = number_format( $cash + $card + $check, 2 ); $cash = number_format( $cash, 2 ); $card = number_format( $card, 2 ); $check = number_format( $check, 2 ); Do any formatting after the math
EDIT
Use str_replace() rather than preg_replace() to strip out any $, then it's simple addition rather than needing to do the array_sum(), though I'm not sure where any $ is likely to come from if the values are DECIMAL 10,7 from the database
$cash = (float) str_replace( array('$',','), '', $cash ); $card = (float) str_replace( array('$',','), '', $card ); $check = (float) str_replace( array('$',','), '', $check ); $total = number_format( $cash + $card + $check, 2 ); $cash = number_format( $cash, 2 ); $card = number_format( $card, 2 ); $check = number_format( $check, 2 ); (assumes that , is your thousands separator in the string values for $cash, $card and $check when doing the str_replace()
EDIT 2
To convert the $cash array to a sum of its values, having cleaned up any $ or , in the strings:
$cash = array ( 0 => '$1729.13', 1 => '0.00', 2 => '$1,234.56' ); function cleanArrayValues($value) { return (float) str_replace( array('$',','), '', $value ); } $cash = array_sum(array_map('cleanArrayValues',$cash)); I've added an extra value into the $cash array just to demonstrate.
You'll need to filter $card and $checks in the same way, using the cleanArrayValues() callback function (if they're all arrays)