use strict;
use warnings;
use Set::CrossProduct;

my @ops = qw( * + - / );
my $expr = '2006 == ' . join ' %s ', 1 .. 9;

my $xp = Set::CrossProduct->new( [ map \@ops, $expr =~ /%s/g ] );
while( my @attempt = $xp->get ) {
        my $attempt = sprintf $expr, @attempt;
        print $attempt, "\n" if eval $attempt;
}
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Makeshifts last the longest.