When you translate COBOL to Perl or any other c family languages, you need to be careful with the math. c family languages are not designed to take care of the precision to great details, and rounding could also be an issue.

To resolve this kind of issues, one way is to use bignum pragmas in certain modules.

For example:

use strict;
use warnings;

#use bignum;

print 215.88-214.89;
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Without bignum it gives you 0.990000000000009, but with bugnum it gives you 0.99. In certain aplication areas, this makes a big difference.