Have you ever pried off one wafer of an Oreo cookie perfectly so that all the cream sticks to the other wafer? Well, scientists at both Princeton University and MIT figured out how that happens. The Oreo-making machine squirts warm cream filling onto the bottom cookie. That filling oozes into the cracks, making it stick well. The machine drops the second wafer on after the filling has cooled, so that wafer isn’t glued on as well. The machine stacks all the Oreos facing the same way, so once you figure out the first cookie, you can pick the right wafer to twist every time!

*Wee ones:* What shape is the cookie part of an Oreo?

*Little kids:* Each Oreo is cookie, cream, cookie. If you stack 1 Oreo on another, how many layers of cookie do you have? *Bonus:* How many more layers of cookie than cream do you have?

*Big kids:* If a box of Oreos has 2 rows of 16 Oreos each, how many Oreos are there in total? *Bonus:* The scientists bought giant boxes of 500 Oreos each to study them. How many Oreos are in 4 boxes that size?

*The sky’s the limit:* If in a stack of 100 Oreos, every 4^{th} twisted Oreo (starting with the 4^{th}) makes a popping sound, and on every 5^{th} Oreo (starting with the 5th) the cookie cracks, how many cracked Oreos don’t say pop?

__Answers:__

*Wee ones:* A circle.

*Little kids:* 4 cookie layers. *Bonus:* 2 more cookie layers (4) than cream layers (2).

*Big kids:* 32 Oreos. *Bonus:* 2,000 Oreos.

*The sky’s the limit:* 15 cookies. You crack 20 cookies, but every 4^{th} one pops: cookies # 20, 40, 60, 80, and 100. So you subtract 5 from the set.