*[Photo by jaaron.]*

Welcome to the ** Math Teachers At Play** blog carnival — which is not just for math teachers! We accept entries from anyone who enjoys playing around with math, as long as the topic is relevant to students or teachers of preK-12th grade mathematics.

Some articles were submitted by their authors, other were drawn from the back-log in my blog reader, and I’ve spiced it all up with a few math jokes courtesy of the Mathematical humor collection of Andrej and Elena Cherkaev.

Let the mathematical fun begin…

## ELEMENTARY CONCEPTS

[Photo by David Mezzo Van Couvering.]

Q:How do you tell that you are in the hands of the Mathematical Mafia?

A:They make you an offer that you can’t understand.

- If you don’t know how to interpret this photo, check out Now THAT is the way to learn math, where
**David Van Couvering**writes about how his daughter learned the times tables at her Waldorf School.

- For several great ideas about teaching math to young children, check out this classic post: Math the Play Way.

- It looks to me like
**Amy Lapain**and her son are having a lot of fun with Crazy Math. Amy explains, “My son has ADHD, but when I write out practice sheets like this it actually helps him focus.”

- “Next time you need to teach about math with money, budgeting, and keeping a running total,” says
**Misty**, “look no further than your next shopping trip. Turn the whole thing over to your child and let them learn how they need all that math in the ‘real world’.” Check out the way she Gives Kids Money and a Budget.

- Without venturing into the “real world,”
**Jimmie**stages a shopping trip to let her daughter play around with Hands-on Estimating.

## ARITHMETIC

[Photo by jimmiehomeschoolmom.]According to statistics, there are 42 million alligator eggs laid every year. Of those, only about half get hatched. Of those that hatch, three fourths of them get eaten by predators in the first 36 days. And of the rest, only 5 percent get to be a year old for one reason or another. Isn’t statistics wonderful? If it weren’t for statistics, we’d all be eaten by alligators!

**Heather**presents a great way to integrate all kinds of problem solving in your math program by Math Journaling.

**Lefty**shares an interesting set of problems in Math problems of the week: 3rd grade Everyday Math vs. 1920s Math. Or if 3rd grade is to easy for your students, try giving them these: Math problems of the week: 6th grade Connected Math vs. Singapore Math.

- Here is something my daughter would love — using algebra to learn arithmetic!
**Mr. L**describes how Schools Turn Algebra into Child’s Play in Lebanon, Oregon.

- I haven’t had time to sit at the computer and write recently, so here’s a treat from the archives for my carnival entry: Putting Bill Gates in Proportion.

- Not sure whether your students have fully mastered the basics?
**Dan Greene**offers a review of arithmetic with his Numeracy Curriculum.

## BASIC ALGEBRA & GEOMETRY

[Photo by John-Morgan.]One evening Rene Descartes went to relax at a local tavern. The tender approached and said, “Ah, good evening Monsieur Descartes! Shall I serve you the usual drink?”

Descartes replied, “I think not.”

— and promptly vanished.

**Child’s Play**continues an excellent series on the mathematics of circles with Math Monday: Trampoline Math!

**Nick Hershman**offers an updated set of lessons about Systems of Equations/Inequalities.

**Jonathan**explores a variety of transformations in Teaching off topic 4.**Joshua Fisher**gives the topic a twist in 45 Degree Rotations About the Origin.

- Have you ever wondered how people ever managed to calculate Square roots with pencil and paper?
**Brent Yorgey**explains the Babylonian method.

**John Cook**explores a few more tidbits about the golden ratio in Golden ratio and special angles.

## ADVANCED MATH

[Photo by thejonoakley.]“Do you love math more than me?”

“Of course not, dear – I love you much more.”

“Then prove it!”

“OK… Let R be the set of all lovable objects…”

- My students have been enjoying (or, as Chickenfoot would put it, “suffering through”) a few of
**Dave Marain’s**challenge problems: Classic Exponent Challenge for SATs, Algebra 2, Math Contests, and A Recurring Problem for SATs (Functions).

**Robert Talbert**shares insight gained from 16 years of teaching experience in Four things I used to think about calculus, and what I’ve replaced them with.

- How would you like to experience mathematical vertigo? Check out the film series Dimensions.

- Mark C. Chu-Carroll warns us that You can’t write that number; in fact, you can’t write most numbers.

- Does anyone know where the
**Carnival of Mathematics**has gone this time? [Update: It will be here next Friday.]

## MATHEMATICAL PUZZLES

[Photo by fdecomite.]

Boring Theorem:

All positive integers are boring.Proof:

Assume the contrary. Then there is a lowest non-boring positive integer. Who cares!

**Dana**shares the fun of playing with Soma Cubes, one of my all-time favorite 3-D puzzles. If you’d like to try making your own set, look at History of Soma Cube, which describes the basic blocks and includes plenty of puzzles.

- For a wide variety of challenges from the
**American Mathematics Competitions**, check out MAA MinuteMath.

**Pat Ballew**remembers some of the giants upon whose shoulders we all stand in Logic Diagrams, A Brief History.

- Speaking of logic puzzles, could you reason your way to freedom if you were one of 4 Buried Soldiers?

- And don’t forget to send in your solution to Monday Math Madness #33: Prime Factorization this weekend!

## ABOUT TEACHING MATH

[Photo by chrisrobinson1945.]“The number you have dialed is imaginary. Please rotate your phone 90 degrees and try again.”

“What’s your favorite thing about mathematics?”

“Knot theory.”

“Yeah, me neither.”“In modern mathematics, algebra has become so important that numbers will soon only have symbolic meaning.”

**Maria Miller**presents Homeschool Math Blog: Lockhart’s Lament, saying, “This is an old post — an inspirational example of a math problem where one is able to ‘create a profound simple beauty out of nothing’.”

- Find out how several teachers answer the question, “Do You Analyze Student Work to Improve Your Teaching?”

**Dan**tells us about an intriguing, inexpensive method to boosts kids’ test scores…and an expensive remedy that doesn’t really work like you might think: Things that Make your Kids Smarter…and Things that Don’t.

**Jason Dyer**revisits last summer’s hot topic of controversy in The “Multiplication is Not Repeated Addition” Research.

- Have you started planning for next year yet?
**Lara DeHaven**reviews the free Mathematics Enhancement Programme in My Math Curriculum Pick.

And 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 June 12 at Homeschool Bytes. If you would like to contribute, please 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!

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For some reason, this post has got like a gazillion spam the past several weeks, so I’m closing comments. Not that anybody real is commenting on it, anyway, so long after publication. But just in case anyone

wantedto leave a comment, I thought I should explain…