# Maria's Math News, Vol. 69, February 2013

I love teaching, and I love math. This newsletter is my way of reaching out and helping you to teach it, too.

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Hello everyone! I had fun working with some of the topics in this edition as they tie in with geometry and art; I hope you do too!

~Maria

1. Math Mammoth news
2. Star polygons
3. Möbius strip
4. Geometric art design with 7 circles
5. Tidbits

## 1. Math Mammoth news

I'm working on revising grade 5, currently working on the 5-B answer key. I hope to have that available in 1 month.

## 2. Star polygons

I recently put a few exercises about star polygons into the new Math Mammoth grade 5 geometry section that I'm revising, and thought I'd share some printables here as well.

What are star polygons? They are polygons that look somewhat like a star. You can form them by joining the vertices of a regular polygon in a certain manner. For example:

I put the star polygon worksheets on this page. They are PDF files, enabled for annotation, so you can actually fill them in (draw in them) using Adobe Reader on the computer.

You will find a worksheet from pentagram (5 points) all the way up to dodecagram (12 points). Here's one example (nonagram worksheet):

Then there are also printable worksheets with empty polygons where students can experiment and create their own star polygons.

They are at this link.

On-line, self-paced, multimedia math help that is reasonably priced.
Pre-algebra, Algebra, and Geometry lessons that include instruction, "Try These" problems to check understanding, and worksheets with step-by-step answer keys.

Go to www.teacher4-u.com/Offer.html for your free lesson.

## 3. Mobius strip

Möbius strip is a fun object to play with. The video below by Vi Hart has a little story to go with the idea: Wind and Mr. Ug.

My girls were wondering how come Wind can come home and there's already a message ready left by Mr. Ug? When did Vi write that when doing the video? And why does Wind never meet Mr. Ug?

See if you can solve the mystery...

While they were watching, I made my girls some Möbius strips and let them draw a line or a "fence" around them. I cut one apart in the middle to show what happens when an "earthquake" hits... Like I said, simple and fun.

I found the video via this blog post that uses a similar idea, but with Moebius ants (easier to draw!).

## 4. Geometric art design with 7 circles

I got inspired by the blogpost Art School | Geometric Design with Islamic Art where Deborah shows how to make a neat flower design with seven circles, using a compass, and then coloring it using 2, 3, or 4 colors (or however many of your own). I think it ties in neatly with mathematics, and lets students practice drawing circles with a compass.

My girls loved this art/math project. Here's one of the pictures they made (titled Blue Jay of the Sky):

The step-by-step instructions for the flower design are on my blog (you can leave comments, too).

## 5. Tidbits

• It's Snowing Angles
This is a cute hands-on math project with snowflakes and ties in with learning acute, obtuse, and right angles, and how to measure angles with a protractor. The author provides a printable PDF of snowflakes. By Relentlessly Fun, Deceptively Educational Mom blog.

• Placing the square root of 7 on a number line
This is such a creative idea to use within a math lesson! I admire Fawn for thinking of it and going through with it. Her students got to do some great mathematical thinking & geometric drawing. Ties in with square roots & Pythagorean theorem.

• Math Teachers At Play #58
Hat tip goes here! A great blog carnival, from where most of this newsletter's ideas came from.

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Till next time,
Maria Miller