#!/usr/bin/perl

use strict;
use warnings;

foreach my $n (0, 1, 10, 24, 25, 26, 49, 50, 51, 74, 75, 76) {
    printf "%3d: %3d\n", $n, 50 * sprintf "%.0f" => $n / 50;
}

__END__
  0:   0
  1:   0
 10:   0
 24:   0
 25:   0
 26:  50
 49:  50
 50:  50
 51:  50
 74:  50
 75: 100
 76: 100