The code given in the OP would work fine, provided that all the values are in an array (@busi). If they're independent scalars ($busi1, $busi2, etc., as in the example of what currently works), then it won't.

BluGeni, I strongly recommend putting your values into an array, then using

for (@busi) {
  $_ =~ s/-//g;
}
[download]

(or, more idiomatically, s/-//g for @busi;) instead of working with the variables as independent scalars - any time you have a series of variables named $foo1, $foo2,..., that's a pretty strong indication that what you really want is an array.

If you need help getting these values into an array, just show us the code that you're currently using to assign their values and we can show you how to modify it to use an array instead.