## Playful Math Carnival #100 via Three J’s Learning

Check out the new carnival of playful math for all ages at Three J’s Learning blog. You’re sure to enjoy this great collection of puzzles, math conversations, crafts, teaching tips, and all sorts of mathy fun.

Wow, the 100th Math Teachers at Play! Such an honor to put together this milestone edition.

• It is written with a 1 and two 0s
• Square number (10 x 10)
• It is a sum of two squares 64 + 36

It’s so cool to see carnival number 100. Thank you to ALL the hosts and to everyone who has participated over the years!

Past carnivals are still full of mathy treasure. Check them out:

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## Ebook Sale at Smashwords

If you read ebooks, check out this great sale at Smashwords. Through the end of July, all of my playful math ebooks are 25% off — and my daughter’s novel Banished (The Riddled Stone, Book One) is free!

Just remember to enter the discount code (SFREE for Banished, and SSW25 for all the others) at checkout.

Click an image below to read more about that book. The discount codes are also listed on each book’s description page.

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## Education Bloggers: Share Your Post!

[Image by Omar Omar (CC BY 2.0) via Flickr.]

If you are a homeschooler or classroom teacher, student or independent learner, or anyone else who writes about math, now is the time to send in your favorite blog post for next week’s Math Teachers at Play (MTaP) math education blog carnival.

Have you noticed a new math blogger on your block that you’d like to introduce to the rest of us? Feel free to submit another blogger’s post in addition to your own. Beginning bloggers are often shy about sharing, but like all of us, they love finding new readers.

Don’t procrastinate: The deadline for entries is this Friday, July 22. The carnival will be posted next week at Three J’s Learning.

### Need an Idea-Starter?

If you haven’t written anything about math lately, here are some ideas to get your creative juices flowing…

• Elementary Concepts: As Liping Ma showed, there is more to understanding and teaching elementary mathematics than we often realize. Do you have a game, activity, or anecdote about teaching math to young students? Please share!
• Arithmetic/Pre-Algebra: This section is for arithmetic lessons and number theory puzzles at the middle-school-and-beyond level. We would love to hear your favorite math club games, numerical investigations, or contest-preparation tips.
• Beginning Algebra and Geometry: Can you explain why we never divide by zero, how to bisect an angle, or what is wrong with distributing the square in the expression $\left(a + b \right)^2$? Struggling students need your help! Share your wisdom about basic algebra and geometry topics here.
• Advanced Math: Like most adults, I have forgotten enough math to fill several textbooks. I’m eager to learn again, but math books can be so-o-o tedious. Can you make upper-level math topics come alive, so they will stick in my (or a student’s) mind?
• Mathematical Recreations: What kind of math do you do, just for the fun of it?
• About Teaching Math: Other teachers’ blogs are an important factor in my continuing education. The more I read about the theory and practice of teaching math, the more I realize how much I have yet to learn. So please, fellow teachers, don’t be shy — share your insights!

### Would You Like to Host the Carnival? Please?!

Hosting the blog carnival is fun because you get to “meet” new bloggers through their submissions. And there’s a side-benefit: The carnival often brings a nice little spike in traffic to your blog. If you think you’d like to join in the fun, read the instructions on our Math Teachers at Play page. Then leave a comment or email me to let me know which month you’d like to take.

### Explore the Other Math Carnivals

While you’re waiting for next week’s Math Teachers at Play carnival, you may enjoy:

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## Review: Math & Magic in Wonderland

Are you looking for a fun book to read over the summer? I just finished Lilac Mohr’s delightful Math & Magic in Wonderland, and I loved it.

Highly recommended, for kids or adults!

A Jubjub bird disguised as a lark,
Borogroves concealing a snark,
When you’re in Tulgey Wood, you must
Be careful whom it is you trust…

With the discovery of Mrs. Magpie’s Manual of Magic for Mathematical Minds, Lulu and Elizabeth embark on an exciting journey to a realm inspired by Lewis Carroll’s poetry. The twins must use ingenuity and sagacity to solve classic logic puzzles that promise to uncover the book’s secrets and earn them The Vorpal Blade. In this interactive novel, the reader is invited to play along with the two heroines on their grand mathematical adventure.

Do you have the smarts to help Lulu and Elizabeth outwit the frumious Bandersnatch?

It’s time to enter Wonderland and find out!

–from the back cover of Math & Magic in Wonderland by Lilac Mohr

### What I Liked

Puns, poetry, and plenty of puzzles. Tangrams, tessellations, truth-tellers and liars. History tidbits and many classics of recreational mathematics.

The sisters Lulu and Elizabeth seem real — though perhaps more widely read than most of us. They are different from each other. They make mistakes and have disagreements. But they never deteriorate into the cliché of sibling rivalry that passes for characterization in too many children’s books.

In each chapter, the girls must solve a language, math, or logic puzzle to proceed along their journey. Then a “Play Along” section offers related puzzles for the reader to try.

No matter how challenging the topic, the book never talks down to the reader.

### What I Didn’t Like

… Um … Honestly, I can’t think of anything.

Since it’s traditional to criticize the editing of self-published books, I will say this: There was at least one place where the wording seemed a bit awkward. I would have phrased the sentence differently. But don’t ask me to identify the page — I was too caught up in the story to bother jotting down such a quibble. And I tried flipping through the book as I wrote this post, but I can’t find it again.

Unless you hate logic puzzles and despise Lewis Carroll’s poetry.

But for everyone else, this book is truly a gem. If you like The Cat in Numberland or The Man Who Counted, then I’m sure you’ll enjoy Math & Magic in Wonderland.

Disclaimer: Like almost all book links on my blog, the links in this post take you to Amazon.com, where you can read descriptions and reviews. I make a few cent’s worth of affiliate commission if you make a purchase — but nowhere near enough to influence my opinion about the book.

### And Now for the Giveaway

Lilac offered a paperback copy of Math & Magic in Wonderland for one lucky reader of Let’s Play Math blog.

The giveaway is done. Congratulations, Keshua!

• Tell us about your favorite language, math, or logic puzzle book! Or share a book you’ve been wanting to read.

## Playful Math Carnival #99 via Eat Play Math Blog

Check out the new playful math education carnival at eat play math blog. Math art, tessellations, review games, problem-solving challenges, and all sorts of mathy fun. Not to mention, Raspberry Tiramisu!

Welcome to the Math Teachers at Play #99 Blog Carnival, a monthly smorgasbord of links to bloggers all around the internet who have great ideas for learning, teaching, and playing around with math…

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## 10 Ways to Celebrate World Tessellation Day

Guest post by Emily Grosvenor.

June 17 marks the first-ever World Tessellation Day, a holiday I created to bring awareness to the fun of finding and making tessellations.

Will you celebrate with us?

Here are 10 great ways to play with tessellations, learn about them, and introduce your children to a math concept that opens a variety of creative learning opportunities.

A tessellation is a tiled mosaic pattern of the same shape laid out over and over again, repeating into infinity. Tessellations can be found in nature, or they can be created by people. Learn more at these websites:

## FAQ: He Won’t Stop Finger-Counting

My oldest son has somehow developed the horrid habit of counting on his fingers. We worked on the math facts all summer. He knows the answers in simple form, such as 9 + 4, but if it’s in a bigger problem like 249 + 54, he counts up to add or counts down to subtract, all using fingers. My younger children have no problem with mental math, but he can’t seem to get it. Are there any tips or tricks to stop this?

Counting on fingers is not a horrid habit, it is a crutch. Please think for a moment about the purpose of crutches. The blasted things are an uncomfortable nuisance, but there are times when you can’t get anywhere without them. And if you need them, it does you no good for a friend to insist you should crawl along on your own.

That is how your son feels right now about his fingers. He is struggling with something his younger siblings find easy, and he can tell that you are frustrated. His confidence is broken, in a cast, and needs time for healing. So he falls back on what he knows he can do, counting up the answer.

Think positive: this means he still believes that math ought to make sense — that to understand what he is doing is more important than to guess at an answer. You want him to value sense-making, because otherwise he will try to memorize his way through middle school and high school math. That is the road to disaster.

“Schools spend a lot of time working with young children to get these facts memorized, but many children aren’t ready for that task yet. They’ll count on their fingers, and may be reprimanded for it.
“What happens when a person becomes embarrassed about counting on their fingers? If they still want to think, they’ll hide it. That’s the better option. The worse option that way too many students choose? They start guessing. When math becomes too incomprehensible, or not living up to someone else’s expectations becomes too painful, many students give up on math, and then they just guess.
“We count on our fingers as part of a thinking process. Perhaps the thing I want to figure can be memorized. But if I haven’t memorized it yet myself, the most efficient way to figure it will likely involve fingers.

—Sue VanHattum
Philosophy

### The Problem of Transfer

What you describe is called the problem of transfer, and it is one of the huge, unsolved problems of education.

We can train someone to do a simple, limited task such as answering flash cards. But how do we get that knowledge to sink in, to become part of the mind, so they can use it in all sorts of different situations?

No one has figured that out.

There is no easy solution. It requires patience, and providing a variety of experiences, and patience, and pointing out connections, and asking the student to think of connections, and lots more patience.

### Some Things to Try

It might help to do fewer math problems in a day, so you can take time to work more deeply on each one. Talk together about the different ways you might solve it. Make it a challenge: “Can we think of three different ways to do it?”

In math, there is never just one way to get a solution. Thinking about alternatives will help your son develop that transfer of skills.

Or pick up some workbooks that target mental math methods. The Mental Math workbook series by Jack Hope and Barbara and Robert Reys will help him master the techniques your younger kids learned without effort. It may still take him longer to do a calculation than what you are used to with the other children, but these books will give him a boost in recognizing the types of mental tools he can use.

Here are a few of my previous blog posts that include mental math tips:

Or perhaps encourage him to keep using his fingers, but to switch to a more efficient system, such as Chisenbop. According to math education expert Jo Boaler, research shows that finger-counting supports mathematical understanding.

### Mental Math: A Battle Worth Fighting

Jumping into mental math is hard for an older child who wasn’t taught that way. I believe it’s a battle worth fighting, because those mental math techniques build understanding of the fundamental properties of numbers.

But the main goal is for him to recognize his options and build flexibility, not to do each calculation as fast as possible.

And be sure he no longer needs those crutches before you try to take them away.

Photo credits: “Stryde Walking To School on his New Crutches” by Jim Larrison and “Silhouette of a boy” by TimOve via Flickr. (CC BY 2.0)

This post is an excerpt from my book Let’s Play Math: How Families Can Learn Math Together—and Enjoy It, as are many of the articles in my Let’s Play Math FAQ series.

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