A Day in Digitopolis, Part I

day in digitopolis part 1We’ve all wanted to jump into books. Who doesn’t, for example, want to go to Diagon Alley and hit the shops? Join Hazel for stories in the Honeycomb? Explore Babilonium with Candy Quackenbush? Or sail the skies with Matt Cruise on the Aurora? Part of my job at the Cotsen Children’s Library is to bring these places to life for kids, and this month, we headed to The Lands Beyond to visit Digitopolis, the mathematical kingdom in The Phantom Tollbooth.

The math event was intended for children ages 4-10, and my goal was to make it full of exploration, demonstrations, games, challenges, and unexpected connections. And by the four million eight hundred and twenty-seven thousand six hundred fifty-nine hairs on my head, I think we did it!

A Day in Digitopolis took place in the atrium of Princeton University’s Frick Chemistry Laboratory, a soaring, three-story structure of glass and metalwork. Here’s our welcome desk with two student volunteers and Pi balloons.

digitopolis welcome deskBut before I get started on all the details, I’d like to introduce our event collaborator, Bedtime Math. Founded by Laura Overdeck, Bedtime Math is a NJ-based nonprofit organization that provides playful, zany math problems for parents to do with their kids everyday. In addition to sharing their content through their books, e-mail, and free app, they created Crazy 8s, an after-school math club that has been launched in over 6,000 locations nationwide. These guys know, and love, math.

bedtime math booksBedtime Math brought 3 fantastic activities to the event: Spy Training, Beach Ball Party, and Glow-in-the-Dark Geometry. Here’s Spy Training, which was all about codes and ciphers…

spy trainingAnd here’s Beach Ball Party, which involved counting, stacking, and chasing beach balls determined to make a break for it.

beach ball partyIt also involved Ellen Williams (who you last spotted being pelted with marshmallows in this post) inflating dozens and dozens of beach balls for kids at the event. That’s her in the lower right corner of the photo, hard at work. Very impressive lungs has our Ellen (did I mention she sings in multiple choirs?).

But the total show stopper was Bedtime Math’s Glow-in-the-Dark Geometry. This took place in a darkened classroom off the main event floor. Here, kids could build illuminated structures with glow stick bracelets and styrofoam balls. The results were totally amazing.

glowing geometrySome kids decided to use the original plastic connectors that came with the bracelets to make unique geometric creations. Here’s one of my favorites. A series of loops that, when spun, becomes a sphere!


Bedtime Math was recently invited to the White House to take part in an early STEM learning summit. Seriously. When it comes to amazing math connections for kids, Bedtime Math has it down!

Moving to a different section of the event floor, we find the fabled number mines of Digitopolis. In the book, Milo, Tock, and the Humbug learn that numbers are, in fact, excavated out of the earth, much like jewels and precious stones. The talented Maria Evans from the Arts Council of Princeton built the mine you see below, but we built another one for a later event. You can find the step-by-step instructions here.

number mines 1The mines were stocked with an assortment of wooden numbers. I used 4″ numbers I found online at Woodcrafter. If you’d like a cheaper option, I recommend printing paper numbers on card stock.

At the event table, kids reached into the mine, extracted a number, and then decorated it with a combination of metallic markers and glitter markers. We also had plastic gems and glue on hand for some additional bling.

number mines 4number mines 5

number mines 2The mines were staffed by high school volunteers from the Arts Council, who were suitably decked out in miner helmets.

number mines 3Elsewhere in Digitopolis was the “Fibonacci Forest,” hosted by the Stony Brook-Millstone Watershed Association. This table focused on math in nature. Specifically, symmetry, shapes (like spheres, hexagons, spirals), fractals, and Fibonacci numbers. The Watershed brought a ton of items for kids to touch, connect with, and explore (including my personal favorite, a gorgeous nautilus shell).

nature math 1nature math 2The Watershed also did a cool fractal tree project. It involved a half-sheet of green paper, brown markers, and rulers (here are the instructions if you’d like to see them).

nature math 3We decorated the finished fractal trees with bird and leaf stamps, but you can also just use markers or color pencils.

nature math 4And speaking of wildlife, how about some zebra math? We were delighted to be joined by Princeton University Professor Dan Rubenstein from the Department of Ecology and Evolutionary Biology. Among other things, Dan does field work with African zebras.

zebra math 1Some researchers believe that zebra stripes exist to confuse predators. So Dan and his constituents developed “Dazzle Confusion,” an iPad game in which kids “become the lion” and tried to tap black, white, or striped moving targets to determine which one is most difficult to hit.

zebra math 2At the end of the game, the program tabulated the kids’ results and displayed them on a large screen. As the event progressed, the results continued to accrue. This lead to conversations about data collection, measurement, central tendencies, and averages.

zebra math 3It’s worth noting that although there was much variation on kids’ “strikes” on the targets, there was a strong trend (p < .08) showing that the striped targets were hardest to hit! How’s that for some real world math?

Continuing with the technology theme, the Princeton Women in Computer Science designed an original math game for kids using Scratch, a visual programming language developed by MIT.

scratchHere’s a screen shot of the game, which was created by sophmore Lucy Lin. If you’d like to test drive the game yourself, here’s the link.

scratch screen shotThe game was cool, but even cooler was the fact that there was another laptop running tandem to the gaming laptops that showed all the algorithms behind the Scratch program. And volunteers were on hand to answer any and all questions about computing. They also had a couple of encryption puzzles for kids to crack.

Meanwhile, the Princeton Chemistry Outreach Program (we’ve exploded things with these guys before) was busy making awesome math / science connections with kids. Dr. Wagner and her students ran hands-on experiments with parts per million, vitamin c clocks, and timed invisible ink.

chemistry outreach 1chemistry outreach 2chemistry outreach 3For those who prefer their math undiluted, the Princeton University Mathematics Club came out en force to host a “Playful Problems” table. Here, kids found a plethora of logic puzzles, word problems, visual puzzles, calculator tricks, the works!

math club 1math club 2There were 12 different activities for children ages 4-10. The activities ranged from easy to moderately difficult. Here’s an example of our simplest puzzle, which was created by Casandra Monroe (whom you first met here). Here’s the template if you’d like it.

milo number grid puzzleBelow is a list of what we offered at the event table. In addition to using Google to find some of these puzzles, Math Wizardry for Kids (Barron’s, 1995) and How to be a Math Genius (DK Children, 2012) were terrific resources.

  • Suduko
  • Lattice multiplication
  • Logic grid puzzle
  • Matchstick puzzles (we used Q-tips instead of matchsticks)
  • Milo number grid maze (see above)
  • 24 Game
  • Multiplying by 9 finger trick
  • Make a paper star with only 1 cut
  • Superimposed shapes puzzle
  • Visual sequencing puzzle
  • Word problems
  • Birthday calculator trick

Important! If you put together your own Playful Problems table, make sure you provide an answer sheet for each problem. That way, parents and kids can check their answers or get a little hint. Also important! No matter how easy the puzzle, provide an answer sheet (you don’t want younger kids to think that their puzzle was too “easy” for a solution sheet).

For those wanting a bit a exercise with their mathematics, we had a giant 16′ x 16′ floor maze (building instructions for it are in this post). Kids had to get from start to finish in the maze – without making a single right-hand turn. If you got stuck, the solution was posted on some glass doors opposite the entry to the maze.

no right turn maze at eventBy the way, did you notice the cute play cart parked in the upper right corner of the above image? That’s one of our “Trio of Treats.”

trio of treatsI always try to include something for the littlest patrons, so I bought 3 adorable food carts and stocked them with math play sets. The food carts are by KidKraft (Sweet & Sunny Lemonade Stand) and the play sets are by Learning Resources. We used  Piece-A-Pizza Fractions, Number Pops, and Count ‘Em Up Popcorn.

And, because little kids love to take things in and out of containers, I bought a fabric basket for the pizza cart, a plastic box with a hinged lid for the ice pop cart, and a clear container for the popcorn cart. After the event, we donated the carts and math sets to a local non-profit preschool.

trio of treats customerOne of the most popular event tables, however, was “Visit the 4th Dimension.” It was hosted by scienceSeeds (whom you first met here, and then again here).

scienceseeds 1At the event table, kids learned about the different dimensions (1st is a line, 2nd is a square, 3rd is a cube, 4th is a tesseract). ScienceSeeds brought their 3D printers to the event and made models. You can see a tesseract in progress below. Awesome.

scienceseeds 2Kids could also make 3D models of their own using drinking straws and plastic connectors. You can buy the plastic connectors online (from Strawbees). However, scienceSeeds has a die cut machine and was able to purchase the die cuts (from Accucut) and make their own connectors from plastic sheets (from Grafix).

scienceseeds 4Like I said, their table was hopping – they estimate they went through at least 3,500 straws!

scienceseeds 3The thing I liked most about the project is that there was no limit to the shape, size, or intended use of the 3D models.

3D model 13D model 23D model 53D model 33D model 4

If plastic connectors are not in your budget, I’ve seen similar activities that used straws and pipe cleaner pieces (like this one), or sculptures that that involved cutting and sliding the ends of bendy straws into one another (like this one). I’ve also seen toothpick and marshmallow, (or toothpick and gum drop) geometric structures. But I tend to avoid those because of food allergies.

Whew! Believe it or not, I’m only halfway through all the event activities! You can check out Part II here…prepare to meet Digitopolis’ famous celebrities, get a bit of hands-on history, listen to some musical fractions, and view some truly stunning representations of infinity…

Flannel of the Future

flannel board 2015Some of you may recall this post, in which I visited my friends at scienceSeeds and reported on all the cool science toys they are currently playing with. There was one toy, however, that I didn’t include because I wanted to do a special post on it later.

The time has come for that post.

Get ready to usher your story time flannel board into 2015…may I introduce…the brilliant…the amazing…the mesmerizing…conductive thread! Yes, this thread conducts electricity, which means that your flannel can be rigged with lights!

You’ll need:

  • 1-2 pieces of felt (i.e. flannel)
  • 1 sewing needle
  • A length of conductive thread
  • 1 coin cell battery holder
  • LEDs (3mm or 5mm size are recommended)
  • 1 coin cell battery
  • Scissors
  • Hot glue (optional)

The good news is that all the electrical components listed above will cost you less than $10. A 30 foot bobbin of the thread is $2.95, and the LEDs are between 20¢-50¢ each. A battery holder is about $1.95, and the coin cell batteries, which can be purchased just about any retail store, are between $1-3 dollars (the one you see in the image below is size CR 2032). scienceSeeds buys most of their supplies from SparkFun Electronics, an online company.

electrical suppliesSince we were using lots of LEDs, Lindsay, our scienceSeeds flannel artist, decided to do 2 layers of flannel. The black “background” layer held the thread and the batteries, and a colorful top layer hid the stitching. The results were colorful, tidy, and sturdy. Here’s what the back of our flannel numbers looks like:

rigged upFirst, use the conductive thread to sew a coin cell battery holder to a piece of felt. It’s important that the battery holder is tightly connected to the felt. Lindsay recommends hot gluing the battery holder to the felt first, and then stitching the holder’s connections to the felt with the thread.

Next, push the legs of an LED through the felt. Curl the legs into circles using a small pair of scissors, jewelry pliers, or needle nose pliers.Then stitch the legs to the felt with the thread.

curled leg and threadBecause you’re making a circuit, it’s essential to connect negative to negative and positive to positive. Therefore, the same thread that is connected to the negative post of the battery holder needs to be connected to the negative LED leg. Likewise, the same thread that is connected to the positive post of the battery holder needs to be connected to the positive LED leg.

Worried you won’t be able to rig things up correctly? Worry no more. The battery holder’s negative post is clearly marked, and the negative leg of an LED is always the shorter of the two.

led leg and holderYou can just connect one LED, or you connect a train of them. One important thing to note: if you’re using just one LED, the battery tends to heat up (as opposed to multiple LEDs in a strand, which share the power load). If you’re using just one LED, you might consider adding a resistor (i.e. an electrical component that limits the flow of a current through a circuit). Many LEDs already come with resistors.

When everything is connected, slip a coin cell battery into the battery holder. Your LEDs will activate, and your flannel board will glow! We discovered that the weight of our LEDs, battery holders, and coin batteries made our flannel numbers drop off the flannel board (Viva Las Vegas!). But the problem was quickly solved with a bit of Velcro.

velcroYou could also move beyond flannel boards! Here are a few projects from the scienceSeeds workshop. A handsome owl puppet with glowing eyes…

owlA Halloween treat bag with color-changing LEDs! Oooo!

bagA truly marvelous super hero mask.

maskIn addition to conducting electricity, the thread can also be used decoratively. You can see it here, adding some silver highlights to the mask.

thread on maskOK…you have the tools and the know-how. Cue up Pachelbel’s Canon in D, go forth, and illuminate!


Many thanks to scienceSeeds for rigging up the fantastic 2015 flannel!

Science Friday

the eggbotWhile I certainly do my fair share of fiction-focused programs, I consider non-fiction programs to be (dare I say it?) just as much fun. And for today’s adventure in non-fiction, we’re talking science!

We’ve offered some interesting science programs in the past. Take, for example, the Chemistry of Magic, in which we demonstrated the real science behind seemingly magical reactions. Or this Rube Goldberg engineering program. Or even this humble preschool story time that featured the life stages of a butterfly. This week, to get a healthy dose of vitamin “S,” I dropped in on my friends at scienceSeeds.

scienceSeeds team

Team scienceSeeds: John, Michal, and Lindsay

ScienceSeeds is a local science enrichment center for grades K-8 . It was founded in 2008 by Michal Melamede. While raising her children, she noticed a lack of hands-on, age-appropriate, science and engineering opportunities. So Michal decided to establish a business that would encourage curiosity, exploration, discovery, and scientific thinking.

Visiting scienceSeeds is always fun. Especially when they let me play with their toys! Here are a few of their current favorites. Perhaps one or two will inspire a little science at your next program?

JOHN’S FABULOUS CANDELABRA

lamp 2I have to start with this one because I’m such a hot glue devotee. This is an LED lamp with hot glue stick shades! It was designed by John to demonstrate circuits, fiber optics and light behavior. He used a hot glue gun to hollow out the bottom of 5 hot glue sticks, and then rigged up a series of little LED bulbs on a simple circuit. Everything was attached to a foam core base, and then the base was wrapped with decorative duct tape. I love it.

HYDRAULIC BUTTERFLY

butterflyThis is another project designed by scienceSeeds staff to teach hydraulics. Using two water-filled syringes and tubing, the butterfly lifts its wings up and down. The syringes are from a medical supply company, the tubing is from a science catalog, the base is wood, the wings are made from foam board, and the butterfly’s body is a clothespin. A little duct tape here and there and you’re ready to go. They also have versions with an owl, a bat, and a dump truck!

FOAM BOARD AUTOMATAUN

star boxOne final project from scienceSeeds’ workshop! This one demonstrates how simple machines and mechanisms work. Turn the crank and the movement of the wooden gears and rods causes the star to spin. The base is made from foam board, the sticks are bamboo skewers, and the gears are little wooden circles purchased from Michael’s craft store. A little hot glue and duct tape seals the deal.  And just look at this sweet double gear version!

bee boxMark my words…I’m GOING to find a way to work a foam board automataun into a story time project. It shall be done. Oh yes, it shall.

THE EGGBOT

the eggbotThis is a recent acquisition at the workshop. It’s the EggBot, an art robot that can draw on round surfaces like eggs, light bulbs, ping pong balls, ornaments, etc. It hooks up to your computer and, with some lovely freeware, will take a design or image and put it right on your object! scienceSeeds is using it to teach CNC and automated design. Here are a couple test subjects…

lightbulbsAlas, an EggBot kit like the one above retails for $219, so it’s well out of my budget. The company that sells it is called Evil Mad Science LLC. Hah hah hah! Minions not included.

CONFETTI VACUUM CLEANER

vacuumThis is a modification of a cardboard kit the staff tested. They found that a 1 liter bottle and plastic propeller worked much better than a cardboard tube and propeller. The foam board base holds a simple circuit that connects to a motor. As the motor spins the propeller, it creates a wind tunnel in the bottle that sucks up pieces of confetti. It’s the perfect way to teach engineering and air flow. It’s wildly popular with the kids too.

THE 3-DOODLER

3-doodlerIt might be a little hard to see this in the photo, but this device lets you do 3-dimentional drawings! That thin green line you see isn’t drooping down from the tip of the doodler. It’s rising up from the piece of paper and standing on its own! You insert little plastic sticks of various colors into one end of the “pen.” The plastic emerges in liquid form out the other end, but quickly hardens. With some practice, you can “draw” amazing 3D creations like these:

popcafe everestrobotscienceSeeds likes to use the 3-Doodler for their 3D modeling workshops, sometimes in conjunction with their 3D printer. A 3-Doodler pen retails for about $100, and additional plastic sticks are approximately $10 for 25. I noticed that the pen makes a loud whirring noise while being operated (a little louder than an electric toothbrush). The staff also mentioned that after extended periods of use, you can smell burning plastic. The smell bothers some kids. But those things aside, it’s a cool little drawing tool.

I’ll leave you with a photo of scienceSeeds’ classroom space. Look at the cheerful red cabinets! The under-the-counter adjustable storage! The cool green chairs! Now imagine it packed full of kids creating, discovering, building, and innovating. Fantastic.

room shot