# Sir Cumference Lesson! {Euler’s Law}

There are so many benefits to reading and engaging with math stories. But I think students will get even more out of the story if the learning doesn’t stop once the last page is read. Therefore, I have been creating activities to go along with some of my favorite math books! (If you missed the activities for Math Curse by Jon Scieszka, be sure to check it out!).

Honestly, I  love all the Sir Cumference books by Cindy Neuschwander. They are so fun and so clever! And the way she weaves math into the story is just beautiful! 🙂

The first book I have chosen to look at is:

As usual, there are so many fun plays on words, and the story line is similar to the “Sword in the Stone,” so if students are familiar with that, they will appreciate it even more.

In this story, King Arthur has issued a challenge to the knights in the form of a riddle. Whoever solves the riddle and finds the sword, Edgecalibur, will be the future king. By solving the riddle, Radius and Vertex uncover what is known in the math world as Euler’s Law, or Euler’s Polyhedron Formula. While this may sound boring or intimidating to young learners, the mathematics is actually quite simple. 😉 The first activity in this pack allows students to explore this formula further.

(NOTE: If you would like, I have designed the first activity to be used with this set of 3D shape nets. You will need to download that free packet as well, if you would like to use them. Otherwise you can use your own.)

While the most obvious math to be learned is Euler’s Law, there is also a lot of algebraic reasoning woven in, so I have created a couple of early algebra activities to go along with this story as well, in case your students are older.

This packet includes 4 different activities, along with teaching tips and answer keys to the algebra questions.

I hope you find these activities useful, but most of all, I hope you will have fun incorporating this engaging story into your math classroom!

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Do your kids love the Sir Cumference books? Then check out the complete collection of lessons to use with all the books by Cindy Neuschwander!