#!/usr/bin/perl

use strict;
use warnings;
use feature 'say';

my @numbers = qw(
    0.254
    0.255
    0.256
);

foreach my $number (@numbers) {
    my $rounded = sprintf '%.2f', $number;
    say "$number => $rounded";
}

foreach my $number (@numbers) {
    $number += 100;
    my $rounded = sprintf '%.2f', $number;
    say "$number => $rounded";
}

0.254 => 0.25
0.255 => 0.26
0.256 => 0.26
100.254 => 100.25
100.255 => 100.25
100.256 => 100.26

$number = sprintf '%.15f', $number;

0.254000000000000 => 0.25
0.255000000000000 => 0.26
0.256000000000000 => 0.26
100.254000000000005 => 100.25
100.254999999999995 => 100.25
100.256000000000000 => 100.26