Keurig's K-Cups have found a second life, helping elementary school students solve math problems.

Keurig says all its single-serve, environmentally problematic coffee K-Cups or pods won't be recyclable until 2020. But Peter Cameron's Grade 6 students at St. Elizabeth School in Thunder Bay, Ont., have found an innovative way to reuse them.

From building prisms to figuring out fractions, the cups have become an important part of the class's math curriculum.

Now Cameron and his students are on a campaign to encourage schools across the globe to join them in recycling coffee pods in the classroom.

"It's become really the base around my whole math program," Cameron says. "I'm not kidding when I say they are the best math manipulatives that I've ever used."

Stuck with 800 K-Cups

Much fuss has been made about the billions of plastic coffee pods being dumped in landfills thanks to a global obsession with single-serve coffee machines. In North America, Keurig dominates the market with the K-Cup.

Cameron's students began searching for a creative way to reuse the cups when faced with the prospect of tossing more than 800 of them.

Earlier this year, the students were volunteering at a local shelter and were tasked with taking the grounds out of donated K-Cups. The shelter didn't offer single-serve coffees, but still wanted to brew the grounds.

Rather than discarding the empty pods, the students took them back to class. "We really didn't know what we were going to do with them at that point, but we just thought we should repurpose them," Cameron says.

The cups sat in a box until one day, as a math exercise, the teacher helped his students figure out the volume of the stash. They then calculated how much less volume they took up when stacked.

"They got it because it was relevant to them," he says.

Math goes 3D with K-Cups​

Check out how K-Cups can be used in the classroom to make math more interesting. (Peter Cameron)

It was a eureka moment for Cameron who realized the plastic pods can be used as a tangible tool to help solve all sorts of math problems.

For example, instead of having students draw a 3D prism on paper, they now build one with K-Cups and then figure out the dimensions.

The coffee pods are also useful for showing patterns, geometric shapes, multiples of numbers and, because they come in two different colours — blue and white — the students can use them to figure out fractions and ratios.

Cameron has also created a K-Cup challenge where he tests a student's math skills using pods. For example, he'll ask a student to build a rectangle or create an acute angle.

"Instead of them doing it on paper, they're building their acute angle. It's three dimensional on their desk," he says.

Students enjoy the hands-on learning. "It makes things a lot easier," says Alyssa Lentz, 11. "If we're trying to draw a rectangular prism, it's easier to do it with K-Cups because you just build it."

Amanda Stockla, 12, agrees. "You can move them around and it makes it a lot more fun. It's sort of more of a class thing, so we're all like figuring it out together," she says.

The class continues to collect used K-Cups and keeps finding new uses for them, including trekking them to the Kindergarten class to help teach addition and subtraction. Cameron also found a recipe to turn the leftover coffee grounds into playdough for younger students.

The Grade 6 students also discovered they could use the cups as mini-pots for planting herbs.

"We planted basil and dill and cilantro for Mother's Day," said Amanda. Students in Peter Cameron's Grade 6 math class also use K-Cups to plant seedlings. (Peter Cameron)

Save the K-Cups

Buoyed by his class's success, Cameron is now spreading the word to other schools via social media. He's designed a program called K Cups 4 Classrooms that includes a resource guide for teachers and a video where his students demonstrate the versatility of the pods.

​He even created the hashtag: #KCups4Classrooms.

So far, the project has inspired 10 elementary schools across North America.

Cameron just got a tweet from a junior high school class in Gillette, Wyo., that has collected 600 K-Cups and will start using them next week.

"We set quite a lofty goal of a million K-Cups saved [in schools] worldwide," said the teacher.

His class has also written a letter to K-Cup inventor John Sylvan. In March, Slyvan told CBC Radio's As it Happens that he regrets creating the non-recyclable coffee pod.

"Regret no more!" the class wrote to Sylvan, explaining to him that his invention now has a second purpose in life – making math fun.