help with float numbers

Learned members of the list: I have quite a frustrating problem that I *think* involves floating-point ('double') numbers. I have the following code: $Total = array_sum($Activity); if ($Total == 100) { // do some stuff } else { $Message = "Total is $Total! Please check your numbers.\n"; } If $Activity has values like (25 , 25 , 25 , 25), then it works just fine. But if $Activity is an array of the following: (71.8 , 5.6 , 5.6 , 8.5 , 8.5) I get the message "Total is 100! Please check your numbers." I don't understand!!! If Total is 100, then why doesn't that meet the condition of the first if-statement ?! I suspect it has something to do with the way PHP deals with integers vs. floating-point numbers. Yes? For my purposes, $Activity may have all integers, all decimals, or a combination of both like (25, 25, 25, 12.5, 12.5). I'm using PHP 4.3.1. What can I do to allow for this? How do I compare an integer (100) to what MAY OR MAY NOT be a float ($Total)? Many thanks, Paul D