Today is Ice Cream Sandwich Day! This sweet treat was invented in the early 1900s in New York City, when an ice-cream cart guy mashed vanilla ice cream between two thin cookies. By the way, the ice cream cone was invented around the same time, by wrapping a waffle around the scoop. Then the sandwich took new forms, like the chocolate-chip Chipwich in 1981. But as New York Times writer Ligaya Mishan found out, New York City alone has sandwiches made with coconut-jackfruit ice cream, ice cream flavored with grown-up liqueurs, and open sandwiches with no top layer at all. Mix and match your own cookies and ice cream to invent your own cool treat!
Wee ones: If an ice cream sandwich has a cookie, then a layer of ice cream, then another cookie, how many layers does it have?
Little kids: How many complete sandwiches can you make if you have 7 chocolate chip cookies handy? Bonus: How many would you need to make 7 sandwiches?
Big kids: If you have 4 kinds of cookies — sugar, Oreos, chocolate-chip, and oatmeal — and 4 flavors of ice cream — coconut, mint, peanut butter, and pistachio — how many wild cookie-ice cream sandwich combos can you make? (Assume each sandwich uses 2 of the same cookie.) Bonus: When did the Chipwich, born in 1981, have its 25th birthday?
Answers:
Wee ones: 3 layers.
Little kids: Just 3, since that will use 6 cookies; you’d need 8 to make 4 sandwiches. Bonus: 14 cookies (2 cookies apiece).
Big kids: 16 kinds, since each of the 4 pairs of cookies can go with any of the 4 flavors. Bonus: In 2006.
Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking before she could walk, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.