Posts Tagged ‘volume’

popcorn challenge

By Kristina

You are trying to decide what popcorn containers to select for a school movie night.

For the four types, calculate:
1) Volume
2) Surface Area
3) Cost per Cup of Popcorn (hint: you’ll need to find out some more information).

The challenge: come up with new popcorn containers that hold the same volume but have less surface area (so they cost less to produce).

Screen shot 2013-03-05 at 9.18.13 AM

Authentic Movie Night: The small plastic tub costs $1.99. It measures 5.25″ across the top and is 5″ tall. The large plastic tub costs $2.99. It measures 7″ across the top and is 7.25″ tall.

Pop-open Popcorn: These cardboard tubs have dimensions 4″W x 8″H. They come in packages of 100 for $22.99.

Movie Time Red: This square plastic tub is 7” by 7” and costs $9.99.

The kids figured out that they had to find the number of cubic inches per cup, so I showed them how to do the conversion by typing it into Google.

photo (2)  photo (1)


Some kids figured out to take the second tub and turn it on its side so that the opening would be on the long side (holding the exact same volume but removing a bunch of the cardboard).

I liked this activity for having students manipulate real-world shapes and present their work in front of others. Some groups in one class didn’t get to this challenge activity because they needed more time practicing volume calculations, so they served as judges for choosing the best modifications to the popcorn boxes.


let them eat cake

By Kristina

The world is serendipitous. I ran into Hannah Lesk (grad student from HGSE who worked on Radix for a bit) at the LearnLaunch conference yesterday, and she gave me a cool idea for surface area and volume from Wayne Thiebaud’s Cakes.


Now pondering my design of problems relating to icing, pricing, and packaging. I’m thinking of having them calculate the cost of icing all the cakes in the picture (based on surface area), and then figuring out how many cakes they could store in a school store pantry before selling them for prom fundraising (using the cake caddy).


I’m also thinking of doing some pan conversions.