Rice Krispie Conic Sections

After seeing Rice Krispie Conic Sections on Shawn’s blog, I knew I had to make them for my class.  I’m so glad I did.  They were amazing.  They are actually very easy to make, and totally worth it.  We have been doing parabolas all year, but it was so cool to cut a conic and SEE a parabola inside!

Screen Shot 2015-02-25 at 10.13.13 PMTips for anyone who wants to make them.  I used snow cone cups that I got on Amazon.com.  I first looked at Target, but there were no snow cone cups to be found in January.  Once the treats were made and set, the snow cone paper just tore off very easily.

Screen Shot 2015-02-25 at 10.11.34 PMThe Rice Krispie Treat recipe is not on the Rice Krispies box, but on the marshmallow package.  It took a double recipe to fill 18 snow cone cups.  I only have one Alg 2 class, so this was fine.  But, if I had more students I would probably not fill the cups up as full, so a double recipe would fill more cups.

I gave each group of students two snow cone krispie treats (so we could make a full conic) and some plastic knives, and then we were off!  I first had them cut a circle off of the top.  Then we moved to ellipses and parabolas.  For the hyperbola, I had them stick their two cones together.  I was impressed at how well it went.  Sometimes you do an activity that sounds great, but doesn’t really give you the full effect.  The rice krispie cones turned out better than I even thought they would!  And of course, the best part about Rice Krispie Conic sections is that you get to eat them!  This was worth its weight in gold today during the LAST period of the day before 8 inches of snow was expected to fall!

14 thoughts on “Rice Krispie Conic Sections

  1. I think this might be even better than breaking out the play dough when we start slicing up prisms. The snow cone cups are so perfect for making a cone-shaped Rice Krispie Treat! I wish I could find some triangular shaped cups!

  2. I made 50 cones last night. I bought the paper water cup cones – just 4 oz size. It still took 4 recipes. I have 150 students over two days. I haven’t decided if I’ll make more tonight for the “b” day bunch or if we will use one cone per three kids. Not much sweetness in sharing though.

  3. Pingback: End of the year Work | Math Middle In

  4. Pingback: Precal files: Conics | Insert Clever Math Pun Here

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