use strict;
package Module1;
use Exporter 'import';
our @EXPORT_OK = qw(compute_value);

sub compute_value {
  # do the computation
}

1; # this is required, see perldoc perlmod

##</code><code>##

use strict;
use Module1;

my $variable1 = Module1::compute_value();

##</code><code>##

use strict;
use Module1 qw(compute_value);

my $variable1 = compute_value();