Playful Math Carnival #106

Do you enjoy math? I hope so! If not, browsing this post just may change your mind.

Welcome to the 106th edition of the Math Teachers At Play math education blog carnival — a smorgasbord of links to bloggers all around the internet who have great ideas for learning, teaching, and playing around with math from preschool to pre-college. Let the mathematical fun begin!

By tradition, we start the carnival with a puzzle in honor of our 106th edition. But if you would like to jump straight to our featured blog posts, click here to see the Table of Contents.

Try This Puzzle

If you slice a pizza with a lightsaber, you’ll make straight cuts all the way across. Slice it once, and you get two pieces.

If you slice it five times, you’ll get a maximum of sixteen pieces. (And if you’re lucky you might get a star!)

  • How many times would you have to slice the pizza to get 106 pieces?

Click here for all the mathy goodness!

Visualizing Word Problems with Bar Model Diagrams

A friend emailed me, frustrated with her child’s math lesson on bar diagrams: “Why do they have to make it so complicated? Why can’t we just solve the blasted problem?”

I told her bar models themselves are not the goal. The real question for parents and teachers is:

  • What can you do when your child is stumped by a math word problem?

To solve word problems, students must be able to read and understand what is written. They need to visualize this information in a way that will help them translate it into a mathematical expression.


Bar model diagrams are one very useful tool to aid this visualization. These pictures model the word problem in a way that makes the solution appear almost like magic.

It is a trick well worth learning, no matter which math program you use.


“Visualization is the brain’s ability to see beyond what the eyes can see, and we can develop visualization in many ways.”

The Bar Model Explained

“A bar model is a way to represent a situation in a word problem using diagrams — in particular, using rectangles.”

“This is one of the ideas that children learn in mathematics: the use of diagrams to represent quantities, especially quantities which are unknown.”

Word Problems from Literature

I’ve written a series of blog posts that explain bar model diagrams from the most basic through to solving multistep word problems. Check them out:

I’ve started working on a book about bar model diagrams, and I’d love to hear your input. Have you tried using them? Do they help your children? What questions do you have?

CREDITS: Videos and quotations from Dr. Yeap Ban Har’s YouTube channel. “Girl doing homework” photo (top) by ND Strupler and “math notebooking equal fractions” by Jimmie via Flickr (CC BY 2.0).

howtosolveproblemsWant to help your kids learn math? Claim your free 24-page problem-solving booklet, and you’ll be among the first to hear about new books, revisions, and sales or other promotions.

New Book: Multiplication & Fraction Games

It’s here! My long-awaited upper-elementary Math You Can Play games book has finally hit the online bookstores.

Multiplication & Fractions features 25 kid-tested games, offering a variety of challenges for school-age students. Children master several math models that provide a sturdy foundation for understanding multiplication and fractions. The games feature times table facts and more advanced concepts such as division, fractions, decimals, and multistep mental math.

Free Online Preview

Click here to find Multiplication & Fractions at your favorite bookstore.
170 pages, ebook: $5.99, paperback: $17.99.

Multiplication & Fraction Games

multfrac-300Maybe you never really understood what multiplication means or what fractions are? As long as you start with an open mind and are willing to engage playfully, the activities in the book can help you as you help your kids.
Anecdotally, these two areas are the first major stumbling point for students in their math studies. The sequencing in the book will help kids develop a strong foundation.
Kids (and parents!) find these games fun. I’ve been field testing math games for the last 18 months and keep seeing how engaged kids get when playing math games.

— Joshua Greene
Multiplication & Fractions Math Games from Denise Gaskins (a review)

Chapters include:

  • Mathematical Models: Learn the basic pictures that help support your child’s comprehension.
  • Conquer the Times Tables: Enjoy practicing the math facts until correct answers become automatic.
  • Mixed Operations: Give mental muscles a workout with games that require number skills and logical thinking.
  • Fractions and Decimals: Master equivalent fractions, work with decimal place value, and multiply fractions and decimal numbers.

If you are a parent, these games provide opportunities to enjoy quality time with your children. If you are a classroom teacher, use the games as warm-ups and learning center activities or for a relaxing review day at the end of a term. If you are a tutor or homeschooler, make games a regular feature in your lesson plans to build your students’ mental math skills.

So what are you waiting for? Clear off a table, grab a deck of cards, and let’s play some math!

Check It Out

It starts with models that are visual explanations of the concepts. Gaskins also breaks learning these concepts into comfortable steps that emphasize patterns and relationships, the real ideas that are behind properly understanding multiplication and fractions (indeed, math generally).
The sequence of games in each section starts by building familiarity and then fluency (speed) to solidify all of that work.

— Joshua Greene
Multiplication & Fractions Math Games from Denise Gaskins (a review)

Multiplication & Fraction Printables

Multiplication & Fraction Printables

Most of the Math You Can Play games use materials you already have around the house, such as playing cards or dice. But this book introduces multiplication and fractions with several games using two special mathematical model card decks.

Click here to download the Multiplication & Fraction Printables, featuring all the math model cards, hundred charts, and game boards you will need for any game in the book.

The Value of Math Games

From Peggy Kaye’s classic book Games for Math:


“Games put children in exactly the right frame of mind for learning difficult things.

“Children relax when they play — and they concentrate. They don’t mind repeating certain facts or procedures over and over, if repetition is part of the game.

“Children throw themselves into playing games the way they never throw themselves into filling out workbook pages.

“The games solidify the achievements of children who are already good at math, and they shore up children who need shoring up. They teach or reinforce many of the skills that a formal curriculum teaches, plus one skill that formal teaching sometimes leaves out — the skill of having fun with math, of thinking hard and enjoying it.

“If you play these games and your child learns only that hard mental effort can be fun, you will have taught something invaluable.”

Peggy Kaye
Games for Math

Sample Peggy’s Games for Math

howtosolveproblemsWant to help your kids learn math? Claim your free 24-page problem-solving booklet, and you’ll be among the first to hear about new books, revisions, and sales or other promotions.

Number Game Printables

One step closer to getting my long-awaited Multiplication & Fraction Games book out — I finished the printables file! At least, I hope I’ve finished. Sometimes it seems like whack-a-typo never ends…

Multiplication & Fraction Printables

Multiplication & Fraction Printables

Click here to download the Multiplication & Fraction Printables, featuring mathematical model cards, hundred charts, and game boards to accompany the upcoming Math You Can Play: Multiplication & Fractions book.

The Multiplication & Fractions ebook will come out sometime in November, and the paperback should follow in time for Christmas. If you’re interested, my newsletter subscribers will get a special introductory sale price whenever the book is published. Join now!

You may also want to check out:

Number Game Printables Pack

Number Game Printables Pack

Click here to download the Number Game Printables Pack, featuring hundred charts, graph paper, and game boards from the first two Math You Can Play books.

Also, 0–99 charts, and bottoms-up versions, too. (See my blog post Math Debates with a Hundred Chart.) And a fun cut-and-fold game board for playing Shut the Box.

Permission to Use These Files

You have permission to copy and use these game boards and worksheets in your own local classroom, home school, math circle, co-op class, etc. But you may not post them on your own website (though you can link to this post, if you like) or sell them. If you’re not sure how copyright works on the Internet, check out Daniel Scocco’s Copyright Law: 12 Dos and Don’ts.

Free-Learning-Guide-Booklets2Claim your two free learning guide booklets, and be one of the first to hear about new books, revisions, and sales or other promotions.

Making Sense of Arithmetic

Homeschoolers have an advantage in teaching math: As our students grow, our own understanding of math grows with them because we see how the ideas build on each other.

This is especially true for those of us with large families. We pass through the progression of concepts with each student, and every pass lays down another layer in our own minds.

If you’d like to short-cut that process, check out Graham Fletcher’s Making Sense of Elementary Math video series. He’ll walk you through the topics, showing how manipulatives help build early concepts and gradually give way to abstract calculations.

“Understanding the vertical progression of mathematics is really important in the conceptual development of everyone’s understanding. This whole Making Sense Series has truly forced me to be a better teacher.”

— Graham Fletcher

Continue reading Making Sense of Arithmetic

FAQ: Trouble Finding the Right Math Program

“I can’t find a home school math program my son likes. We’ve tried Singapore Math, Right Start, Saxon, and Math Mammoth. We subscribed to a month of IXL Math to keep him in practice, but he hates that, too. I know I shouldn’t have changed so many times, but this was our first year of homeschooling, and I was trying to please him. But I’m running out of things to try. Do you think Life of Fred might work?”


You’ve tried all those math programs in one year? Many people recommend that new homeschoolers take a few months off to “detox” from the classroom setting, to relax and enjoy the freedom of making their own choices. But your son might want a few months to detox from his homeschool experience.

I suggest you set aside all those books and focus on games and informal math. Try to avoid schoolish lessons until your son starts to enjoy learning for its own sake. The Internet offers an abundance of creative math ideas.

  • For example, download the Wuzzit Trouble or DragonBox apps to play with, but don’t make it a homework assignment.
  • Or let him choose one of the activities at Gordon Hamilton’s Math Pickle website and explore it for a day or a week or as long as it remains interesting.
  • Browse through the Primary Level 1 or Level 2 puzzles and games at the Nrich Mathematics website for more ideas.

Look for more playful math on my blog’s resource pages:

Explore Big Concepts: Infinity

Math that captures a child’s imagination can make the more tedious work seem bearable. For instance, in the 1920s, mathematician David Hilbert created a story about an imaginary grand hotel with an infinite number of rooms.

Explore Big Concepts: Fractals

Sierpinski-tortillasTake a mental trip to infinity by playing with fractals. Cynthia Lanius’s online Fractals Unit for Elementary and Middle School Students offers a child-friendly starting point.

Fractals are self-similar, which means that subsections of the object look like smaller versions of the whole thing.

Most children enjoy exploring the concept of infinity with hands-on fractal patterns, such as this Sierpinski triangle made of tortilla chips. Talk about what you notice and wonder: How does the triangle grow? How many chips will we need for the next stage?

The Daily Four

If you worry that your son needs to keep practicing traditional arithmetic during his break, try making him a series of Daily Four pages:

  • Fold a sheet of plain paper in half both ways, making four quarter sections.
  • Write one math problem in each part. Choose them from any of your math books.
  • Make sure each problem is different — one addition, one fractions, one multiplication, or whatever — and that none of them are hard enough to cause frustration.
  • Don’t worry about an answer sheet. Show him how to use a calculator to check his work.

You can make up a whole week’s worth of these problem sheets at once, with a balanced mix of problems for each day. Your son won’t feel overwhelmed, but you’ll know he’s reviewing his number skills.

Or download some of the Corbettmaths 5-a-Day practice sheets for him. Some problems may seem too easy while others require concepts he hasn’t studied yet. Easy review won’t hurt anything, but do let him skip the problems that feel too hard.


Credits: “Rock Surfer Boy” by Ken Bosma and “Boy” by Isengardt via Flickr. (CC BY 2.0) Hotel Infinity video by Tova Brown.

Click for details about Let's Play Math bookThis 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.

Free-Learning-Guide-Booklets2Claim your two free learning guide booklets, and be one of the first to hear about new books, revisions, and sales or other promotions.