How to make a QR code out of M&Ms

A while back, I was researching how to print a QR code on a cake, as you do, and stumbled across this mysterious video of a QR code made of M&Ms:

The quality’s kind of poor and the provenance mysterious, so I set to wondering: is it really possible to make a QR code out of M&Ms?

With the students attending last week’s Middle Grades Institute, I set about finding out.

How to make a QR code out of M&MS

Materials:

• Plain M&Ms (we discovered: roughly 1.5 pounds of M&Ms works for 9 students, even taking into account uh, collateral loss during construction)
• Rulers
• Chopsticks (for sanitary food-handling)
• Large white sheets of paper
• Printed QR codes, large enough so they take up most of an 8.5″ x 11″ sheet of paper
• At least 45 minutes
• Information to embed in the QR codes — I linked them to additional YouTube videos showing QR codes made out of hard candy, white mints on a blue background, and Legos.

Method:

Show the mysterious M&M video. Then break into groups of 3, take a giant sheet of white paper, a dish of M&Ms and a ruler, and ask each team to duplicate the pattern of a different QR code with the M&Ms.

Note: remove the yellow M&Ms from the field of play. They will not scan dark enough to serve as “blocks”, but as one group figured out, you can use them as spacers.

Instructions beyond that are optional. All three groups I worked with quickly determined that QR codes are made up of units, and each side is n units long. So with M&Ms as your units, you know each row will be n M&Ms long. And, as mentioned above, the yellow M&Ms make great spacers to be removed at the end.

Not just any flat surface will do

I love it when a plan comes together pic.twitter.com/K0rmx1TdcH

— Tarrant Institute (@innovativeEd) June 27, 2014

Yes, we are building on the floor. Classroom space was at a premium (read: not available), so we staked out a section of hallway and got to it. Reports from the testers indicated that tables would have been infinitely preferable, as in one case, a group had to get their M&Ms to stay put on a ridge in the carpet.

Results

 

Success — with strings attached

 

If worked! @innovativeEd #stem #mgi #vted #mscareercamp pic.twitter.com/Qgf44G2dm1 — Dana Cummings (@dcummingsems) June 27, 2014

Out of our three groups of testers, one was able to construct a functioning QR code, above. Although by “functioning” I mean that the code was scannable with the apps Scan and RedLaser, but not QRafter or QR Reader. (Thank you to Essex Middle School educator Dana Cummings for serving as the official judge and scanning authority!)

One group ran out of time, and one group gave up after trying three different methods of assembly: line-by-line, coloring in squares underneath, and trying to put M&Ms directly on top of the printed sample.

Among the groups, different roles emerged during construction. In each group there was someone who enjoyed separating out all the yellow ones, someone who enjoyed reading out the squares (“3 black! 2 spaces! 1 black, 3 spaces!”) and someone who was handy with the ruler and detail-oriented enough to make very, very neat lines. In fact, when at first the finished QR code wouldn’t scan, the ruler-wielder took a brief moment to straighten two lines that had gone wonky, and that made all the difference.

Also, while I was keen on using chopsticks for food-handling, I was the only one, and the chopsticks generally wound up being put into play as boundaries or used to make minute adjustments at the finish.

For our next trick…

At about the 45-minute mark, focus became our popular but elusive friend who chose to sit elsewhere, leading to a rash of airborne M&Ms (note to self: prepare M&M-physics-velocity lesson plan), M&Ms repurposed into flower and house patterns, and one threat to play Godzilla, stomping through the downtown candy area. These folks took a different tack with wine-gums, using a stenciled, barely visible template under their paper, which might speed things up, but would also have taken a lot of the fun out of the activity.

And my testers did assure me they enjoyed themselves mightily. Although, they commented, next time they want to try it with Skittles.