I'm assuming that you've already got the file reading part down, so my code just takes the shortcut of having nice 8-bit representable numbers in __DATA__. Given that intro, here's a pack / unpack approach.

use strict;
use warnings;

while ( my $num = <DATA> ) {
    chomp $num;
    next unless $num;
    my $bits = unpack "b8", pack "C", $num;
    my $zeros = $bits =~ tr/0//;
    my $ones = $bits =~ tr/1//;
    print <<"OUTPUT";
    Decimal: $num \t\tZeros:    $zeros
    Bits:    $bits  \tOnes:     $ones
    
OUTPUT
}

__DATA__
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