Posts tagged ‘Calculation Nation’

Think of a Number

I love to create math games almost as much as I love to play them.

Calculation NationMy favorite professional project was leading the development of Calculation Nation. And my favorite game on the site is neXtu, though other games on the site may promote more sophisticated mathematical thinking.

I have many reasons to love my wife, not least of which is her creation of the game Dollar Nim. While I can’t take credit for the rules, I will take credit for its analysis and its popularization. (What do you call a wife who makes up a game that gets you a publication credit? A keeper!)

DragonboxRecently, I’ve been frustrated by the lack of games for teaching algebra. I’ll give props to the good folks at Dragonbox, which uses a game environment to teach algebra. But I’m not yet convinced that it leads to deep algebraic understanding; even they admit “to transfer to pencil and paper, children must be explained how to rewrite equations line by line.” They also claim that “in-house preliminary tests indicate a very high level of transfer to pencil and paper,” but that’s the fox watching the henhouse.

So I’ve been thinking about games I can play with my sons that will allow them to engage in algebraic thinking. But I don’t want them to know they’re engaging in algebraic thinking. I have two criteria for all math games:

  • The game mechanics depend on mathematics. The math is not tangential to the game; it is the game.
  • Kids don’t realize (or at least they don’t care) that it’s a math game, because it’s fun.

It pains me to write that second criterion, because math is fun. But I know not everyone shares that opinion. So I do my best to disguise any math learning in the game and then, when they least expect it — BOOM! — I drop the bomb and show them what they’ve learned.

So here’s a game I recently devised.

  • Player A chooses a number.
  • Player B chooses two operations for Player A to perform on the number.
  • Player A performs those operations and then tells the result to Player B.
  • Player B then tries to identify Player A’s number.

These rules leave something to be desired, since Player B could simply ask A to “multiply by 1” and then “add 0,” in which case finding A’s number would involve no work whatsoever. To be a stickler, an additional rule could impose that either addition or subtraction can be used exactly once and that no operation can involve either 0 or 1. In a middle school classroom, I suppose I would state such a rule explicitly; for playing this game with my seven-year-old sons, I opted not to.

We played this game three times on the car ride to school yesterday. One game went like this:

  • I thought of a number (14).
  • Eli asked me to add 3 to my number.
  • Alex asked me to multiply by 3.
  • I told them the result: 51.

Eli then guessed that my number was 16. He had subtracted 3, then divided by 3.

“No!” said Alex. “You added 3 first, so you need to subtract 9.”

“Why 9?” Eli asked. “Daddy only added 3.”

“But he multiplied by 3, so if you subtract first, you have to subtract 3 × 3.”

Eli then realized that my number was 14.

He thought for a second. “Oh,” he said. “I should have divided by 3 first, then subtracted.”

Wow, I thought. This is going even better than I hoped.

Though they didn’t use the proper terminology, the boys had a great discussion about “undoing” operations by performing inverse operations in reverse order. In 10 minutes, they taught themselves how to solve a two-step equation:

3x + 3 = 51

Grace Kelemanik once said that she knew she was being effective when she didn’t have to say a word. She’d watch from the back of the room as students carried the conversation and guided one another to correct mathematical thinking.

I will never claim to be half the educator that Grace Kelemanik is. But yesterday morning, I was pretty darn effective.

I’d love to hear about math games you’ve played with kids, whether you invented them or not.

August 15, 2014 at 11:43 pm 4 comments

Would You Rather Urinate or Calculate When Playing Video Games?

Have you heard about Toylets? They’re interactive urinals. (No, really, I’m not making that up.) Created by Sega, the video game company that gave us wholesome games like Mortal Kombat and Sonic the Hedgehog, Toylets are currently being tested in select locations in Tokyo.

Using a pressure sensor inside the urinal, Toylets measure the strength and location of your urine stream. A small LCD screen above the urinal allows you to play several simple video games. If you’re lucky enough to find a demo site, you can play Milk from Nose, a sumo wrestling game where you try to knock another player out of the ring using the strength of your urine stream (displayed on-screen as a milk spray from your nose). Interestingly, the details of your urination are saved and used as the opponent for the next player. Consequently, the game is somewhat multi‑player. Let’s hope it doesn’t become an MMORPG!

My suspicion is that Calculation Nation, an online world of math strategy games from NCTM, is perhaps more appealing to the crowd who reads MJ4MF.

Recently, a new game, neXtu, was released on Calculation Nation. By going to the site, you can play neXtu as a one‑player game against the computer or as a two‑player game against anyone in the world. (Login is required for the two-player games, but registration is free.) The cool thing is that NCTM has provided HTML code so that anyone can place a link that allows visitors to play neXtu directly on their website. (Theoretically, one could also place a link that allows visitors to play the game directly from a blog post, too — unless you blog on WordPress, which doesn’t allow JavaScript code for security reasons. So, phooey.)

I used this code to place neXtu on the MJ4MF website. You can play neXtu here.

The new game is pretty cool:

The description from Calculation Nation gives a quick overview:

Next to nothing is more fun than capturing your enemy’s pieces! Strategically place geometric pieces with point values on the game board to collect more shapes and points than your opponent.

The gist is that you have triangles, squares and hexagons (each with a certain point value) to place on a board. If you place a piece adjacent to an opponent’s piece and your piece has a higher point value, you capture the opponent’s piece. Both players start with the same pieces and point values, and just as you’d expect the winner is the player with more points after all pieces have been placed.

February 6, 2011 at 6:41 am 1 comment

Math 2.0 Seminar – Calculation Nation

During a Math 2.0 webinar on July 7, I’ll be talking about Calculation Nation®, an online world of math strategy games that I helped to develop as the Online Projects Manager at NCTM.

Information about the talk can be found at

This webinar is FREE.

The webinar will be deliverd through Elluminate online conferencing software. If you’ve not used this software before, please arrive 10‑15 minutes early to make sure that everything you need to participate can be installed on your machine. To join the webinar, go to

July 1, 2010 at 6:14 pm Leave a comment

NCTM Annual Meeting — San Diego

The NCTM Annual Meeting will be held April 21-24 in San Diego. On behalf of the Council, I’ll be presenting the following sessions:

  • Math Joke (Half) Hour
    Wednesday, April 21, 2:30-3:00pm; Convention Center, Room 6E
    (if there’s enough interest, this session will be repeated at 3:15pm in the same room)
  • Online Math Strategy Games for the Middle School Curriculum
    Saturday, April 24, 8:30-10:00am; Convention Center, Room 15A

When not presenting, I’ll be hanging out in the Cyber Cafe (within the exhibit hall), telling folks about all the great classroom resources they can find at Illuminations and Calculation NationTM. Stop by to say hello — and to tell me your favorite math joke!

April 16, 2010 at 12:24 am Leave a comment

About MJ4MF

The Math Jokes 4 Mathy Folks blog is an online extension to the book Math Jokes 4 Mathy Folks. The blog contains jokes submitted by readers, new jokes discovered by the author, details about speaking appearances and workshops, and other random bits of information that might be interesting to the strange folks who like math jokes.

MJ4MF (offline version)

Math Jokes 4 Mathy Folks is available from Amazon, Borders, Barnes & Noble, NCTM, Robert D. Reed Publishers, and other purveyors of exceptional literature.

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