or download this
Arithmetic operators
The binary operators "+" "-" "*" "/" "%" "==" "!=" ">" "<" ">=" "<
+="
and the unary operators "-" "abs" and "--" will attempt to convert
...
listed above will force their argument(s) into integer format, and
return an integer result. The exceptions, "abs", "++" and "--", do
not change their behavior with "use integer;"