It’s been this way for almost 1,000 years.

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The story of the “baker’s dozen” has nothing to do with faulty mathematics (bakers have to be good at basic math) or with a disposition of generosity (bakers have to make a living too), but rather, the 13 items that comprise a “baker’s dozen” most likely started as a response to a law passed almost 1,000 years ago in England under the reign of King Henry III.

Bread is not easily predictable—the time it takes to rise or the amount of air developed beneath the crust of a fresh loaf depends on conditions often uncontrollable to the baker (especially 900 years ago). While King Henry III was ruling England, bakers were developing a reputation for shortchanging their customers by giving them bread that did not weigh as much as what was being paid for. The king determined a specific weight that customers could legally expect a baker to provide for a certain price. The punishment for the baker for breaking this law could include beating and imprisonment. However, the problem remains that yeast in bread dough has a mind of its own and the weight of two loaves of identical size might weigh different amounts—so bakers began throwing in an extra loaf for good measure when customers ordered a dozen. That way the baker would never be found short of the legal standard.

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This luxury has persisted through the centuries even though no such law exists in our society today—and if you’re anything like us, we’re grateful a baker’s dozen doesn’t abide by the same rules of mathematics as everything else. Be it fresh doughnuts, an assortment of cookies, or a box of delicate pastries, there always seems to be room for just one more.