*[Photo by Alex Kehr.]*

Welcome to the ** Math Teachers At Play** blog carnival — which is not just for math teachers! If you like to learn new things and play around with ideas, you are sure to find something of interest. Let the mathematical fun begin…

## ELEMENTARY CONCEPTS

Hare.

Hare.

They mate.

Now there’s three.

Mate again, now five.

And again, now there’s eight bunnies.

[Now thirteen bunnies, and counting. Mom will be pissed off.]

- Misty shares how her Kids Cooking Ideas Turn into Math Lessons: “Why do a fraction worksheet when you can double a cookie recipe instead?”

- Jimmie and Sprite conquer a tough division problem in Rice Krispy Treats Math.

- Looking for a fun way to practice math facts? Kathy offers several resources to help Keep Those Skills Fresh Over the Summer…For FREE!

- Researchers say humans aren’t the only animals that do math. Check out Chicks Who Can Add.

- Tanya Khovanova poses a few Subtraction Problems, Russian Style. Fun!

## ARITHMETIC

*[Photo by fdecomite.]*

I suppose you are two fathoms deep in mathematics, and if you are, then God help you. For so am I, only with this difference: I stick fast in the mud at the bottom, and there I shall remain.

— Charles Darwin

quoted in the Platonic Realms collection

- Aadel’s children are studying
. Check out her post More Penguins! for a collection of math worksheets and other links.*Mr. Popper’s Penguins*

- Katharine Beals poses Math Problems of the Week for 2nd grade, 3rd grade, and 6th grade.

- Brent Yorgey challenges his readers to try Distributing cookies and explains four possible solutions.

- Can your students solve this Small Fractions puzzle from Webmaths?

- And here’s an oldie from my blog reader: Ian Luke Kane presents the Funniest Pie Chart EVER.

## BASIC ALGEBRA & GEOMETRY

*[Photo by fdecomite.]*

Any fool can know. The point is to understand.

- Kate devises a card game to help her students practice multiplying radical expressions in Build Your Own Worksheet.

- Cabin fever drives Sarah Cannon into town, where she discovers a Dose of Cuteness.

- >Jon Ingram shares MA Conference: A circular NRICHing activity: “A fun hour, working through an investigation that was accessible, enjoyable, and has extensions leading in a number of different directions.”

- Jonathan is starting a series on How to teach set theory to freshmen in New York State. Be sure to try his Puzzle: How Many Subsets?

- The guys over at blinkdagger recycle a classic problem in Monday Math Madness #30: Placing Bath Tiles. Send in your answer before next Monday night for a chance to win!

## ADVANCED MATH

*[Photo by Sphinx The Geek.]*

A phenomenon that everybody who teaches mathematics has observed: the students always have to be taught what they should have learned in the preceding course… The average student does not really learn to add fractions in an arithmetic class; but by the time he has survived a course in algebra he can add numerical fractions. He does not learn algebra in the algebra course; he learns it in calculus, when he is forced to use it.

— Ralph P. Boas

[You will have to scroll down a bit to find Boas’ essay.]

Lion Hunting and Other Mathematical Pursuits

- John Cook presents Floating point numbers are a leaky abstraction. This is the first of two blog posts about how computer arithmetic works and what problems to look out for. (Part 2 here.)

- Sam Shah offers a valuable problem-solving mantra in Take what you don’t know….

- Cherish Maunders accepts the challenge of explaining Fourier Transforms to a 13-year-old who is studying basic algebra.

- MIke Croucher presents Simulating Harmonographs, saying, “This is an old one of mine, but it was quite popular — one blog even used one of the resulting patterns as its logo! The equations are relatively simple and should be accessible to any 16+ maths student (or possibly earlier).”

- Dave Marain announces his MathNotations Second Math Contest (FREE). No middle school teams this time, but if you teach algebra 2 or beyond, you should definitely give this a try.

## ABOUT TEACHING MATH

Many teachers are concerned about the amount of material they must cover in a course. One cynic suggested a formula: since, he said, students on the average remember only about 40% of what you tell them, the thing to do is to cram into each course 250% of what you hope will stick.

- Marybeth Whalen shares a wealth of Living Math resources.

- I am sure you will enjoy Heather’s observations, re-posted as A Canadian Teacher’s Perspective on Teaching in London, England.

- I like using quotes to encourage or inspire my students — or just to make them laugh. The Les Pook Miscellany has a full page of favorite Quotations.

- Sue VanHattum felt “too tied to the textbook,” so she is encouraging a new approach: Students Learning Through Teaching.

- My entry for this week: Kitten strongly dislikes math when forced to do it on her own, so I’ve started doing Buddy Math with her. I don’t know how it would work in a classroom, but it’s a great method for tutoring or homeschooling.

That rounds up this edition of the ** Math Teachers at Play** carnival. I hope you enjoyed the ride.

The next installment of our carnival will open on Friday, May 1, at I Want to Teach Forever. To contribute, use this handy submission form. Posts must be relevant to students or teachers of preK-12 mathematics. Old posts are welcome, as long as they haven’t been published in past editions of this carnival.

Past posts and future hosts can be found on our blog carnival index page.

We need more volunteers. Classroom teachers, homeschoolers, unschoolers, or anyone who likes to play around with math (even if the only person you “teach” is yourself) — if you would like to take a turn hosting the ** Math Teachers at Play** blog carnival, please speak up!

I like the quotes, especially the one from Albert Einstein! Here’s another good one from him, “Bear in mind that the wonderful things you learn in your schools are the work of many generations. All this is put in your hands as your inheritance in order that you may receive it, honor it, add to it, and one day faithfully hand it on to your children.”

Great job, Denise! You’re setting a very high standard…

I particularly like those quotes (Halmos’ quote is hysterical).

Thanks for mentioning the Second MathNotations (Free) Online Contest.

Dave

Hi, Michelle & Dave! I’m glad you enjoyed the quotes. I had fun picking them out. Unfortunately, the last line of the Fibonacci quote didn’t quite fit in beside the picture — all 13 syllables were supposed to be on the same line.

Denise,

Wonderful job… I loved the way you presented the topics…

sorry I missed out …. sometimes you just have to take a week off and go to France with family… a dirty job, but I’m willing to do it…..

Will try not to miss the next one…

Pat

Welcome back, Pat! I had a couple of your posts bookmarked to add to the carnival, but I ran out of time for editing. Rumor is that the Carnival of Mathematics will be back next Friday, however, and I’m sure the host will be glad to include you.

Wow! I’m surprised (happily surprised) to see my blog post here. I don’t remember submitting that. LOL

Another great carnival!

If you don’t remember submitting, Jimmie, you probably didn’t. Only about half of the posts here are volunteers. The rest are drawn from my personal blog browsing. I like a full carnival with a balanced variety of topics.

Fantastic job, Denise. I love the quotes too. Thanks for including my post.

I ditto all the accolades. Wonderful!

Thank you all for the encouraging words!

And if any of you would like to speak up for a week as host of the carnival, most of the dates are open. It is a good bit of work to put it all together, but it’s fun, too. (And there’s a benefit to hosting: the carnival provides a traffic boost to your blog, as people come to visit and drop you links!)