Math Teachers at Play #87 via CavMaths

Posted on by Denise Gaskins

mtap87

Puzzles, comics, problem-solving, and mathy conversations with kids‌—‌you’ll find all this and more at the new math education blog carnival. Check it out, click some links, and enjoy!

“Hello, and welcome to the 87th Edition of the monthly blog carnival “Math(s) Teachers at Play”. For those of you unaware, a blog carnival is a periodic post that travels from blog to blog. They take the form of a compilation post and contain links to current and recent posts on a similar topic. This is one of two English language blog carnivals around mathematics…

This month has been fairly busy in the way of maths blogs and we have a treat for you, so to start the carnival here are the submissions we received…”

Click here to go read Math(s) Teachers at Play 87.

Infinite Cake: Don Cohen’s Infinite Series for Kids

Posted on by Denise Gaskins

Math Concepts: division as equal sharing, naming fractions, adding fractions, infinitesimals, iteration, limits
Prerequisite: able to identify fractions as part of a whole

This is how I tell the story:

  • We have a cake to share, just the two of us. It’s not TOO big a cake, ‘cuz we don’t want to get sick. An 8 × 8 or 16 × 16 square on the graph paper should be just right. Can you cut the cake so we each get a fair share? Color in your part.

Bobby Flay German Chocolate Cake

  • How big is your piece compared to the whole, original cake?
  • But you know, I’m on a diet, and I just don’t think I can eat my whole piece. Half the cake is too much for me. Is it okay if I share my piece with you? How can we divide it evenly, so we each get a fair share? How big is your new piece? Color it in.
  • How much of the whole, original cake do you have now? How can you tell?
  • I keep thinking of my diet, and I really don’t want all my piece of cake. It looks good, but it’s still just a bit too big for me. Will you take half of it? How big is that piece?
  • Now how much of the whole, original cake do you have? How could we figure it out?
    [Teaching tip: Don’t make kids do the calculation on paper. In the early stages, they can visualize and count up the fourths or maybe the eighths. As the pieces get smaller, the easiest way to find the sum is what Cohen does in the video below‌—‌identify how much of the cake is left out.]
  • Even for being on a diet, I still don’t feel very hungry…

Continue reading Infinite Cake: Don Cohen’s Infinite Series for Kids

A Review for my Daughter’s Novel

Posted on by Denise Gaskins

“… a captivating fantasy story with a well-thought-out plot … people who like medieval-style fantasies with wraiths, spirits, and even an attacking swamp tree will enjoy the story. I certainly did, and the excitement, adventure, and suspense will easily keep the reader’s attention …”

— Wayne S. Walker
Home School Book Review

Thank you, Mr. Walker!

As a fantasy fan myself, I agree that Teresa did a great job on this book. She improved in every way from Book #1 — more world building, more complex plotting, and a deeper emotional identification with the characters. I can’t wait to see what she writes next.

Check it out for yourself:

Hunted600

Find out how the adventure began:

BanishedKindleCover

Socks Are Like Pants, Cats Are Like Dogs

Posted on by Denise Gaskins

Support This New Book from Natural Math

Socks Are Like Pants, Cats Are Like Dogs by Malke Rosenfeld and Gordon Hamilton is filled with a diverse collection of math games, puzzles, and activities exploring the mathematics of choosing, identifying and sorting. The activities are easy to start and require little preparation.

The publisher’s crowdfunding goal is $4,000. The book is almost ready to go to press, and I can hardly wait to see it!

Review Game: Once Through the Deck

Posted on by Denise Gaskins

Math Concepts: basic facts of addition, multiplication.
Players: one.
Equipment: one deck of math cards (poker- or bridge-style playing cards with the face cards and jokers removed).

The best way to practice the math facts is through the give-and-take of conversation, orally quizzing each other and talking about how you might figure the answers out. But occasionally your child may want a simple, solitaire method for review.

Continue reading Review Game: Once Through the Deck

New Internet Math Reference Pages

Posted on by Denise Gaskins

The Internet boasts a wide-ranging assortment of math websites, and for years I maintained (or mostly neglected) a huge page of reference links. This spring I’ve been working on the paperback edition of my book‌—‌with its appendix of favorite books and internet sites‌—‌and I decided to revise my blog links to match.

Blogging while we watch the tide come in. :)
Blogging while we watch the tide come in.

So this week, I’m in Jeju, South Korea, visiting my daughter who teaches English there. In between seeing touristy sites and gorging ourselves on amazingly delicious food, she took me to a beautiful coffee shop that overlooks the beach in Aewol.

Great place to work on my blog!

The long monster list morphed into eight topical pages. I hope you find something useful.

Playing tourist with two of my daughters at Halla Arboretum.
Playing tourist with two of my daughters at Halla Arboretum.

I will try to keep these pages up to date, but the Internet is volatile. If you find a broken link, you can search for the website by name or enter the defunct URL into the Internet Wayback Machine at Archive.org.

Changing of the guard at Old City Hall, Jeju-si.
Changing of the guard at Old City Hall, Jeju-si.

And if you know of a fantastic website I’ve missed, please send me an email (LetsPlayMath@gmail.com, or use the comment form on my “About” page). I appreciate your help.

Feature photo above by Fractal Ken via Flickr (CC BY 2.0). Korea photos ©2015 Denise Gaskins, all rights reserved. For more math resource suggestions, check out my Math with Living Books pages. They’re not finished yet, but I’ll be working on them next.

Math Teachers at Play #85 via ZenoMath

Posted on by Denise Gaskins

There’s a feast of mathematical games and activities at this month’s Math Teachers at Play blog carnival Enjoy!

86-Purple-fact
“Math Teachers at Play is a monthly blog carnival that compiles posts from several blogs under the theme of teaching math in unique and innovative ways. We’re thrilled to partner with them this edition and couldn’t help ourselves from including some interesting trivia and riddles centered on our edition number – Happy Number 86!

Happy Numbers are numbers whose digits are such that – when squared and added iteratively, the number 1 is reached. For example,

82 + 62 = 100
12 + 02 + 02 = 1
So 86 is a happy number!…”

Click here to read the carnival post at ZenoMath.

Puzzle: Crystal Ball Connection Patterns

Posted on by Denise Gaskins

K4 matchings

In the land of Fantasia, where people communicate by crystal ball, Wizard Mathys has been placed in charge of keeping the crystal connections clean and clear. He decides to figure out how many different ways people might talk to each other, assuming there’s no such thing as a crystal conference call.

Mathys sketches a diagram of four Fantasian friends and their crystal balls. At the top, you can see all the possible connections, but no one is talking to anyone else because it’s naptime. Fantasians take their siesta very seriously. That’s one possible state of the 4-crystal system.

On the second line of the diagram, Joe (in the middle) wakes up from siesta and calls each of his friends in turn. Then the friends take turns calling each other, bringing the total number of possible connection-states up to seven.

Finally, Wizard Mathys imagines what would happen if one friend calls Joe at the same time as the other two are talking to each other. That’s the last line of the diagram: three more possible states. Therefore, the total number of conceivable communication configurations for a 4-crystal system is 10.

For some reason Mathys can’t figure out, mathematicians call the numbers that describe the connection pattern states in his crystal ball communication system Telephone numbers.

TheWizardBySeanMcGrath-small

  • Can you help Wizard Mathys figure out the Telephone numbers for different numbers of people?
    T(0) = ?
    T(1) = ?
    T(2) = ?
    T(3) = ?
    T(4) = 10 connection patterns (as above)
    T(5) = ?
    T(6) = ?
    and so on.

Hint: Don’t forget to count the state of the system when no one is on the phone crystal ball.

Feature photo at top of post by Christian Schnettelker (web designer) and wizard photo by Sean McGrath via Flickr (CC BY 2.0). This puzzle was originally featured in the Math Teachers At Play (MTaP) math education blog carnival: MTaP #76.

New Fantasy Novel by Homeschooled Teen Author

Posted on by Denise Gaskins

Hunted600After months of editing, formatting, proofreading, sweat, and tears:

Teresa Gaskins’s new ebook Hunted: The Riddled Stone ~ Book Two is available now at Amazon worldwide.

You can download the first five chapters here:

To celebrate the release of Hunted, the ebook version of Banished‌—‌the first book in the Riddled Stone series‌—‌will be on sale for 99 cents for the next few weeks.

Math Game: Fan Tan (Sevens)

Posted on by Denise Gaskins

Math Concepts: sorting by attribute (card suits), counting up, counting down, standard rank of playing cards (aces low).
Players: two or more, best with four to six.
Equipment: one complete deck of cards (including face cards), or a double deck for more than six players. Provide a card holder for young children.

How to Play

Deal out all the cards, even if some players get more than others. The player to the dealer’s left begins by playing a seven of any suit. If that player does not have a seven, then the play passes left to the first player who does.

After that, on your turn you may lay down another seven or play on the cards that are already down. If you cannot play, say, “Pass.”

Once a seven is played in any suit, the six and the eight of that suit may be played on either side of it, forming the fan. Then the five through ace can go on the six in counting-down order, and the nine through king can go on the eight, counting up. You can arrange these cards to overlap each other so the cards below are visible, or you can square up the stacks so only the top card is seen.

A Fan Tan game in progress.
A Fan Tan game in progress.

Continue reading Math Game: Fan Tan (Sevens)