$ perl -e '
use warnings;
use bignum;

my $size = 0.01;
my $step_size = 0.01;

while($size < 5){
  $size = $size + $step_size;
  print $size."\n";
}

print "FINAL: ".$size."\n";'


...
4.94
4.95
4.96
4.97
4.98
4.99
5
FINAL: 5