This should work?

my $fmt = '%.02f';
if ( sprintf($fmt, $num1) eq sprintf($fmt, $num2) ) {
   print "they're the same, to two decimal places\n";
}
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Another common way is to decide upon a maximum allowable difference between them, for example, 0.005, and compare them like this:

my $diff = 0.005;
if ( abs($num1-$num2) < $diff ) {
  print "they're close enough\n";
}
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