How Many 2-Cent Stamps Are There in a Dozen?

There are many variations to this riddle, such as, "Which weighs more, a pound of lead or a pound of feathers?" Though an object made of lead would generally weigh more than a feather, a pound of each would be equal because they both weigh exactly 1 pound. In both of these riddles, the key is to focus on the unit (a dozen, a pound) and not the extra information about the object.