Someone else might be able to provide more definitive advice about that

As regards the operation $m % $n, the perlop documentation ( see perdoc perlop ) states:

<quote>
If the operands $m and $n are floating point values and the absolute value of $n (that is "abs($n)") is less than "(UV_MAX + 1)", only the integer portion of $m and $n will be used in the operation
(Note: here "UV_MAX" means the maximum of the unsigned integer type).
</quote>

So perl's calculation of 3335.99999999995 % 3330 ( == 5) is being done as documented.

Cheers,
Not "someone else"