As a gift for the mathematician in your life, or if you know any triplets who love pie, Nina Dunn (no relation to Ellen) of Mendham, New Jersey suggests the Pi Pie. “It’s simple,” says Nina, “Just use your favorite pie recipe and multiply each ingredient by 3.14 (3.14159 if you want to drive yourself totally crazy).”Penelope cautions — don’t attempt this unless you have at least three pie plates and a good calculator on hand.