I'm not sure what you plan to do with the sum once you have it, but you plan to do more vector-y type stuff, then Math::Matrix might be a good fit.
use Math::Matrix;
my $foo = Math::Matrix->new([ 1, 0, 0, 0, 1 ]);
my $bar = Math::Matrix->new([ 1, 1, 0, 1, 1 ]);
my $sum = $foo->add($bar);