my @nums = (5, 10, 15, 20, 25);

##</code><code>##

my $totalSum = 0;
$totalSum += $_ for @nums;

##</code><code>##

use List::Util 'sum';
my $totalSum = sum @nums;

##</code><code>##

my @array = map { $_ / $totalSum } @nums;