Math = Love: Valentine's Day

Thursday, February 14, 2013

Valentine's Day

Today is Valentine's Day.  I told my students that I had wanted to get them each a Valentine.  But, I went to Wal-Mart, and they didn't have any mathematical valentines.  So, I handed each of my students a strip of colored paper.  I told them that I still got them a Valentine; there was just some assembly required.

Without telling them what we were doing, I instructed them to cut their strip of paper in half.  We folded each strip into a mobius strip, one twisted to the right and one twisted to the left.  Then, we glued the two mobius strips together so they were perpendicular to one another.  Right when my students were really starting to wonder what we were making, I forced them to set their mobius strips aside to let the glue dry.  I really enjoyed getting to introduce my students to the concept of a mobius strip.  Only one student had heard of a mobius strip before.  And, she only remembered it from Vi Hart's Hexaflexagon video.

My Algebra 1 students spent the class period reviewing how to graph absolute value equations, finding slope from a table, and measures of central tendency.  Then, we started looking at more word problems together as a class.  I chose EOI practice problems that required more critical thinking skills than particular Algebra 1 skills.  I am trying to expose my students to as many different problem types as possible before the EOI in April.

Of course, my students did not want to do any math today.  They tried every sort of way possible to convince me that there was no reason to do school work on Valentine's Day.  Once we got started with the word problems, I think they actually enjoyed themselves.  We had some great discussions while trying to match scenarios with graphs.  I think I'm going to try to find some time to fit Dan Meyer's Graphing Stories into my curriculum.  

During the last five minutes of class, we finished our mystery valentines.  I instructed the students to cut both of their mobius strips in half.  The students were hesitant to do so.  They were convinced if they cut through the sections that had been glued that it would fall apart.  I assured them that I knew what I was doing.  And, in the end, they were pleasantly surprised to find two interlocking hearts.  It was a lot of fun doing this short activity with my students.  Plus, mobius strips are mathematical.  And, we discussed mathematical terms such as "perpendicular."

Inter-locking Mobius Strip Hearts.
This one isn't the prettiest, but it was the only one that was left behind in my classroom.
Instructions here:   
I really love my job.


  1. That's awesome! Totally saving it for next year. On a side note - I found a card for my boyfriend that said (outside) "There's only one way to describe a Valentine like you" (inside) Algebraic! Now, neither of us understood the card - the back said it's from Cartoon Network so I guess we're out of the loop - but I told him I love algebra and I love him so it was a perfect fit.

    I think next year, too, I want to look at some cartoid equations that make graphs of hearts - they love playing on their calculator and it would be an interesting way to let them see what "those" buttons (trig functions) can do.

  2. hey sarah, add me on facebook, you're great teacher.

  3. My kids love Vi Hart videos! They are fascinated by how much she knows, how great of an artist she is, and how fast she talks (speeding up the video hasn't entered their minds!).

  4. Hi, Sarah,

    I came across your blog via David Wees, and as a fellow mathematics educator (and vegetarian ;) )I thought you might be able to help in spreading the word about an educational TV show for preteens about math that we're putting together. "The Number Hunter" is a cross between Bill Nye The Science Guy and The Crocodile Hunter -- bringing math to children in an innovative, adventurous way. I’d really appreciate your help in getting the word out about the project.

    I studied math education at Jacksonville University and the University of Florida. It became clear to me during my studies why we’re failing at teaching kids math. We're teaching it all wrong! Bill Nye taught kids that science is FUN. He showed them the EXPLOSIONS first and then the kids went to school to learn WHY things exploded. Kids learn about dinosaurs and amoeba and weird ocean life to make them go “wow”. But what about math? You probably remember the dreaded worksheets. Ugh.

    I’m sure you know math is much more exciting than people think. Fractal Geometry was used to create “Star Wars” backdrops, binary code was invented in Africa, The Great Pyramids and The Mona Lisa, wouldn’t exist without geometry.
    Our concept is to create an exciting, web-based TV show that’s both fun and educational.

    If you could consider posting about the project on your blog, I’d very much appreciate it. Also, if you'd be interested in link exchanging (either on The Number Hunter site, which is in development, or on which is a well-established site with 300,000 page views a month) please shoot me an email. We're also always looking for input and ideas from other math educators!

    Thanks in advance for your help,


  5. Hi there! I have an idea for your next blog post. I'm in high school preparing for college and know I want to be a high school teacher. I just don't exactly know what subject. I have been following you blog though :) Could you explain how you decided to be a math teacher and what you like/dislike about your job?

    Thanks much for all of your posts! I enjoy reading your blog!

  6. Super idea!! I love that you were able to celebrate a holiday and introduce a new concept all at once! Sounds like they really enjoyed it!

    Tales of Frogs and Cupcakes

  7. Where are you?? I miss reading your entries :o( Yes, I am a lurker, but I am a faithful one!