Here's the suggestion I offered in the Chatterbox. It keeps an array of running totals:

#!/usr/bin/perl -w
use strict;
$\ = "\n";

my @total;
foreach my $row ( 1 .. 10 ) {
    my @output;
    foreach my $column ( 1 .. 10 ) {
        push @output , $column;
        $total[$#output] += $column;
    }
    print join ',' , @output;
}
# print column totals here
print 'total:';
print join ',' , @total;
[download]

which gives:

1,2,3,4,5,6,7,8,9,10
1,2,3,4,5,6,7,8,9,10
1,2,3,4,5,6,7,8,9,10
1,2,3,4,5,6,7,8,9,10
1,2,3,4,5,6,7,8,9,10
1,2,3,4,5,6,7,8,9,10
1,2,3,4,5,6,7,8,9,10
1,2,3,4,5,6,7,8,9,10
1,2,3,4,5,6,7,8,9,10
1,2,3,4,5,6,7,8,9,10
total:
10,20,30,40,50,60,70,80,90,100