&total calls a sub called total. You don't provide one. You could use sum from the module List::Util thus:

use warnings;
use strict;
use List::Util qw(sum);

my @fred = qw{ 1 3 5 7 9 };
my $fred_total = sum(@fred);
print "The total of  \@fred is $fred_total.\n";
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Prints:

The total of  @fred is 25.
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Update: Bugger, looks like I just answered a "homework" question! :)