Courtesy of Pennsylvania English teacher Kristina Ulmer

It all started with heartbreak and $100 in tips, when in 2014 Kristina Ulmer’s sister headed home with the cash earned from her breakfast tables, but never made it due to a car crash.

Because Katie was always concerned about struggling folks who were less fortunate, Kristina decided to turn the $100 from her sister’s tips into a fitting memorial that would brighten the world–just like her sister always did.

“I knew I had to do something worthwhile with it,” said Kristina, a ninth-grade English teacher near Philadelphia, Pennsylvania.

“I had this really amazing group of students in front of me, and we were reading a dystopian novel, Fahrenheit 451,” Kristin told CBC Radio. “And in the novel, everyone’s obsessed with their screens. They walk around with earbuds in all day long (and) they lack empathy toward each other.”

It was that day, several years after her sister’s death, that she got an idea. Everyone needed a reminder about the importance of being interconnected and the value of helping each other along the way.

So the Hatboro-Horsham District teacher took the $100 she’d been saving from her sister’s purse, added a little more to it, and directed her students to go out into the world with a mission: Do something kind and make a video about it.

Her ‘Kindness Challenge’ has since attracted over $7,000 in donations—enough to sustain it for six straight years. And, it’s created more than 350 acts of kindness—each one unique.

Courtesy of the Hatboro-Horsham School District

A small Christmas tree for a shut-in elderly couple. Hygiene bags for the homeless. A Lego set bought for a random little boy at Walmart. Holiday cards for residents at a veterans home. Fresh cupcakes for teachers. A crate of toys for the dogs and cats living at a local shelter.

One student sewed hats for premature babies. Another has participated in the Kindness Challenge five times – even though she left Kristina’s class long ago.

“The first time I participated in the challenge, I didn’t think it would be possible to make a difference with $20, but I learned that’s really not true,” a student named Sydney told CBC. “You don’t have to have millions – anyone can make a difference.”

Every year, new acts of kindness move Kristina to tears as she combines the videos into a montage that shares the story of her sister, along with the magic created by her students with their $20 bills.

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Hatboro-Horsham School District

“Everything that comes out of those kids’ mouths as they are sharing what they did and what they learned is my sister speaking,” Kristina said in a video by ABC-6. “She’s been gone 10 years now, but her spirit has lived on through all the things people are doing in her honor.”

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“They now understand the impact that something like a small act of kindness could do.”

It all started with $100 in tips—a legacy that’s not going to end anytime soon.

WATCH the ABC News video below—or a longer video of six years of kindness…

VIEW ANOTHER ONE…

SHARE THE INSPIRATION WITH TEACHERS On Social Media…