The 3D printer is a pretty exciting machine. Instead of squirting ink onto paper, it prints with hot melted plastic, which stacks up in layers to build shapes like cubes and spirals. So it didn’t take long for someone to try putting chocolate in the printer. Our fan Chad R. told us about Hershey Company’s CocoJet which prints with melted chocolate. As you can see in this video, the arm that holds the chocolate moves side to side and back to front to squirt the chocolate in the right spots. If you switch from dark chocolate to milk or white, you can even make designs in different “colors.” The question is, will you save that cool shape, or eat it?
Wee ones: What shape are the sides on that chocolate toy?
Little kids: If you print a stripey chocolate with 2 layers of dark chocolate, 2 layers of milk chocolate, then 2 layers of white, how many stripes does it have? Bonus: If you bite off 4 layers, how many are left?
Big kids: If you can print a mini chocolate soccer ball with 4 ounces of chocolate, how many ounces would you need to print 5 soccer balls? Bonus: How many complete balls could you make out of 2 pounds 6 ounces of chocolate? (Reminder: A pound has 16 ounces.)
The sky’s the limit: The chocolate shape shown here is an icosahedron: it has 20 identical triangle sides, where all edges and angles are equal. How many edge bars does the printer have to print in total?
Wee ones: Triangles.
Little kids: 6 layers. Bonus: 2 layers.
Big kids: 20 ounces. Bonus: 9 balls, since you have 38 ounces and 36 is the biggest even multiple of 4 within that.
The sky’s the limit: 30 bars. If the triangles all stood alone without touching, they’d have 60 edges in total (20 x 3). But every edge is shared by 2 triangles, so together the 20 triangles need only half as many edges as that.
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.