It’s National Bake Cookies Day, which means we’d better bake some cookies soon, or at least eat some! You could make your usual circle-shaped chocolate-chip cookies, or make other shapes using a cookie cutter. We’re loving these math-y cookies made by computer science professor Francesco De Comite. The birds lock together perfectly with copies of themselves, like puzzle pieces. They’re from a drawing by a famous artist named Escher, and Francesco made his own cookie cutter to match those shapes. As you can see on the Natural Math website, he also made puzzle-piece lizards, and lined up chocolate-cookie fish mixing with sugar-cookie geese. So now you have ideas for your own cookie puzzles…if you can hold off long enough from eating them.

*Wee ones:* If you’re counting cookies you’ve eaten and you’ve already had 3, what number do you say next?

*Little kids:* If you stack 2 goose cookies, then 3 fish, then 4 more geese, how many cookies do you have? *Bonus:* If you eat 2 of the cookies, at least how many geese do you have to have left?

*Big kids:* If the 1st lizard faces up, the 2nd faces right, the 3rd faces down and the 4th faces left, then the 5th starts over facing up, which way does the 19th lizard face? *Bonus:* If you have enough dough to make 3 more chocolate fish than vanilla geese, and you can make 47 cookies in total, how many of each can you make?

Answers:

*Wee ones:* 4.

*Little kids:* 9 cookies. *Bonus:* At least 4 geese, even if both cookies you ate were geese.

*Big kids:* Down, since the 20th will face left like all multiples of 4. *Bonus:* 22 geese and 25 fish. If you set aside the 3 extra fish, you’d have 44 cookies evenly split.