Book review: “What’s unnatural?” by Jeremiah Dyke

Making abstract entities into characters with their own looks and personalities is a great idea related to many traditions. “Flatland” featured creatures embodying shapes in different dimensions.

More recently, moe anthropomorphisms embody entities such as Wikipedia:

The book “What’s unnatural” by Jeremiah Dyke of Hands on Math has a cute anthropomorphic numeral 1 as its main character. The images overall have peaceful, slow and steady feel to them, which I like a lot.

The character goes through different number lands, largely corresponding to the extension of numbers from natural to real. It’s a useful topic, and representing it spatially makes a lot of sense, given the traditional Venn diagrams showing relationships among numbers.

Here are things I would change in the next version of the book.

Show number properties rather than telling about them. It’s done beautifully for negatives, but not for other number types.

I was concerned about negatives presented as “positive numbers that carry a bar.” A negative number is a single entity, even though it takes two symbols to represent it. The same goes for fractions represented as “numbers chopped into pieces” – a fraction is a number in its own right, a single number at that. This seems like a minor point, but kids get confused around this issue.

I would continue to the land of reals rather than irrationals, because it breaks the previous pattern. Natural-whole-rational-… is the previous adventure, and the next in line seems real, not irrational.

I would use the book with kids for its roleplaying potential, and the strength of its overall travel metaphor. Thank you for making it!

Posted in Grow

Math is Not a Worksheet

httpv://www.youtube.com/watch?v=sBMhZfBzqyQ

Some time ago Maria and I had a chance to present the Moebius Noodles project at an Open Source/Creative Commons event hosted by Red Hat. As we tried to distill our big ideas into a 3-minute presentation, we had to choose the most important points to cover. They are

  • In many ways, young kids already are mathematicians.
  • Beautiful mathematical adventures are all around us.
  • Math is not a worksheet.
  • Freeing ideas and experiences (i.e. through Creative Commons licensing) is critical for success.

Want details? Check out a video of our presentation.

If you are developing, teaching, or playing rich early math games, we want to hear from you!

P.S. Can you tell this was my first public presentation?

Posted in Grow

Gummy Bear Go! Game

Probabilities game for kids

This is the game my son and I are calling “Gummy Bear Go!” even though most of the time we play it with paperclips instead of treats. I got this game from the Russian mathematician Alexander Zvonkin’s book “Math from Three to Seven: The Story of a Mathematical Circle for Preschoolers“.

To play the game all you need is a piece of paper with a grid drawn on it, a pair of dice, and some counters. The grid has 7 rows and 15 columns, although you can certainly make more rows for a longer game. Each cell in the bottom row is numbered 1 through 15.

Decide how many counters each player will have. The first few rounds we played, we each had 3 counters (make sure you can tell your counters apart from the other player’s). Place the counters on the numbered cells. Make sure to not put more than one counter in each cell. Now, roll the dice, add up the dots, find the counter with the cell number corresponding to the rolled sum and move the counter up one row. Repeat until one of the counters reaches the top row. The first to reach the top row wins the game.

When we first played the game, my son placed his first counter on 6, but his other counter – on 1 and his third counter – on 15. If this happens when you try this game, don’t rush to correct your little one. Instead, play along and let him learn from experience. If your child, like mine, doesn’t do well with loosing a game, you can level the field a bit by placing your counters on “impossible” (1, 13, 14, 15) or unlikely to win numbers (2, 3, 11, 12).

Probabilities game

Rolling two dice means that there’s a lot of addition work in this game. Which is great, but keep in mind that practicing additions is not the main goal of the game. I didn’t want to give the answers to my son, but he did need help with the larger sums. So I gave him a ruler that he used as a number line.

Of course, since there were just the two of us playing with a total of 6 counters in the game, most of the numbers were left open. When we happened to roll a sum equal to an unoccupied number, I’d make sure to say things like “ah, too bad neither one of us had a counter on 7” or “hey, 9 again?! I just might play it in the next round!”

At the end of each round we’d stop to survey the game board and note which counters didn’t move at all and which ones “put up a good fight”. I had the idea to mark each round’s winning number.

After the first round, my son’s choice of numbers to place counters on became much more interesting. He clearly understood that his best chance at winning was on the middle numbers – 5, 6, 7, 8, 9. He abandoned the impossibles and after one or two games moved away from the marginal 2, 11 and 12.

simple math game for kids

Finally, after playing this game for a few days on and off, we played one last round that I called “the grand parade”. We put one counter in EACH cell in the bottom row. This way, every time we rolled the dice, something moved. And once the game was over, we surveyed the battle field.

Understanding probabilities with dice

And then we filled out this little table of all the possible roll combinations. That’s a whole lot of additions which gets pretty boring. So instead I suggested to look for patterns. My son quickly noticed the horizontal and vertical patterns.

Finally, I suggested we try to figure out what’s the most likely winning number. To do that, I asked my son to find the smallest sum in the table, 2. Which explained why placing a counter on 1 was a waste of time. Then I asked him to find the largest sum, 12. Which ruled out 13, 14 and 15 once and forever.

Next, we started counting how many of each sum we had in the table. The 2 and the 12 were easy-peasy. It was interesting to see that although he noticed the horizontal and vertical patterns right away, he failed to see the diagonals. But after finding and counting all the 3s and 4s, he noticed the diagonals and after that counting was a breeze. But the best part was that once we were done counting all the different outcomes, he knew right away which three numbers were the likeliest to win. It was so awesome to see him go through the “Aha!” moment! Plus we got to have gummy bears and mini-marshmallows to celebrate!

Posted in Make

Math Goggles #1 – Math-y Librarian

James B Hunt Library NCSU

It’s time to put on the Math Goggles (not sure what these are? Head over here to find out). This week’s Math Goggles challenge is to visit a library. Once there, start looking around for math-y stuff. Once you find it, snap a picture of it. Keep the picture private or share it with us. Remember, there are no wrong answers here and anything goes.

I wasn’t going to do a library challenge for a few weeks except a friend told me about this awesome brand-new university library that was practically a walking distance from me. And they had a BookBot that could find any of the 1.8 million books and get it to you in under 5 minutes. How could I NOT go?!

BookBot at Hunt Library NCSU

The BookBot and the stacks were impressive, made me think of all sorts of math, including algorithms, estimations, and perspective. But what really made me excited were the arm-chairs! This library has a ton of seating options (speaking of estimations), from ottomans and benches to stools and arm-chairs. So check out my math finds (actually, my son found most of them and pointed them out; I was the one who put them in order and took pictures):

square numbers

Ok, so this is a single square ottoman. And four of them are put together to form… another 2×2 square.

square numbers 16

On another square ottoman the upholstery pattern was made up of 16 smaller squares and 9 buttons!

1×1 = 12 = 1

2×2 = 22 = 4

3×3 = 32 = 9

4×4 = 42 = 16

Library Math

These are all square numbers! I was all set to go look for the next square number (25), but got distracted by this awesome chair. My excuse for lounging in it is it’s my 0x0 = 02 = 0.

And now it’s your turn to look for math at a library. Put on your Math Goggles and be a Math-y Librarian this week!

Posted in Grow