## Monday, August 22, 2016

### Book Club Week 4 {Math and Magic in Wonderland}

In chapter 4 of the math adventure novel Math and Magic in Wonderland, we draw circles, find their centers, understand what Pi really represents, and learn about the "rabbit trails" that famous scientist followed.  Kids always do great with geometry because it is so easy to visualize.  I bought my twins new compasses in the "back to school" section of a local store (only about a dollar!) and they spent a lot of time making circle art and investigating the properties of circles...

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Perfect Circles

"A task impossible for a mortal,

Draw a perfect circle portal."

Maybe the task of drawing a perfect circle is not really "impossible for a mortal".  This video teaches you how to draw perfect freehand circles using your fingers as a compass:

If you want to take your compass a step forward, try making this circle-drawing robot:

We didn't have time to make a circle-drawing robot, but the kids were definitely intrigued and it is on our list of projects to try this year.

Instead, we used our compasses to make some crafts from Ed Emberley's Picture Pie:

The books have instructions for making a variety of designs, starting out with circles which are cut in different ways.  This was not only an engaging art project, but also led to a great discussion on fractions!

Your Turn to Play:

• Make some circle art using a Spirograph.  Actually, you're drawing "cycloids", not circles.  A cycloid is created by a point on a circle as the circle is rolled along a line.  Cycloids were an obsession of mathematician Blaise Pascal.

Finding the Center of a Circle

In this video, we follow the instructions in Chapter 4 for finding the center of a circle.

Since we had our compasses out, I also showed the girls a neat way of exploring the sum of the angles of any triangle.  I intentionally didn't begin explaining that a circle has 360 degrees because I think it is more important for them to make the visual connection rather than memorize that the angles of a triangle add up to 180 degrees.

Your Turn to Play:

• The book invites you to follow along as the girls find the center of their circle.  If you didn't have a chance to play along with the story, you can always try it now.

Pi

In the first chapter of the book, we learned that Lulu recites the digits of Pi to calm down.  But what is Pi?  Here's a cute video explaining Pi (and more) from Danica McKellar, the author of Math Doesn't Suck.  (I also loved watching her as a child actress on "The Wonder Years").

Your Turn to Play:

• Be sure to complete the "Play Along" section in Chapter 4, which includes measuring the circumference and diameter of a circle and calculating the ratio.

Rabbit Trails

What rabbit trails did famous mathematicians follow?  I can't recommend these fantastic books enough!

This week, follow your own "rabbit trails".  I invited the kids to make a list of topics they were interested in and questions they had.  We picked a handful of topics, then pulled out encyclopedias and performed online searches to learn more.  One thing led to another, and we were soon following "rabbit trails" and learning so much.  I'll include more details about our explorations in a separate blog post.

What rabbit trails did you follow this week?  Leave a comment and tell us all about them!

Full Book Club Schedule

Here is the Book Club / Math Circle schedule (you can join any time):

Week of August 1st:
• Book Club Kick-Off Party!
• Read Chapter 1: Mrs. Magpie's Manual
• Alliteration
• Memorizing digits of Pi
• Palindromes
• Calculating your age on other planets
• Read Chapter 2: Magic Square
• Making tangrams
• Acute, obtuse, and right angles
• Magic squares
• Adding consecutive numbers using Gauss's trick
• Read Chapter 3: Secret Codes
• Word permutations
• Cartesian coordinates
• Operations on odd and even numbers
• Read Chapter 4: Rabbit Trails
• Drawing a perfect circle
• Making a compass
• Finding the center of a circle
• Exploring Pi
• Famous mathematicians who followed rabbit trails
• Read Chapter 5: Two Worlds Join
• Mobius strips
• Fractals
• Tessellations
• Read Chapter 6: River Crossing
• River Crossing Problems
• Build a boat and explore buoyancy
• Read Chapter 7: Seven Bridges
• Seven Bridges of Königsberg problem
• The power of exponents
• Word ladders
• Thales's method for calculating the height of an object
• Read Chapter 8: Veracity
• Truth-tellers and liars
• Finding a fake coin using a balance scale
• Archimedes buoyancy principle
• Read Chapter 9: To Catch a Thief
• John Napier's Rooster
• Doubling pennies and calculating exponents
• Towers of Hannoi
• Read Chapter 10: The Vorpal Sword
• Square numbers
• Prime numbers
• Fibonacci Sequence
• Relativity and time dilation
• Acrostic poems
• Read Chapter 11: Two Great Powers
• Book Club Finishing Party with Prizes!

Thanks for joining us.  I can't wait to read your comments!

#### 1 comment:

1. Oops 😄 I'm "unknown"
Anyway, we're so excited for week 4. We've already drawn the perfect circle, that video is great and Danica McKellar's Pi song is a favorite here. We can't wait to get started. ☺

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