It might have seemed like a simple gesture, but when sisters Addison and Madison Kessler presented a handmade “thank you” card their bus driver Monday morning, it meant a lot.

“It’s really cute,” said Janice Iwaniuk, who busses students to and from Northside Child Development Center in Niles. “We work on kindness on the bus so its nice for them to give back.”

The Kesslers are just two of hundreds of Northside students participating in the school’s Week of Kindness, which began Monday.

All week long, the students will be spreading kindness to different staff members around the school by singing songs, creating cards or simply saying, “thank you.”

“We want kids to be nice, listen and do,” said Northside Principal Zech Hoyt. “This is just a whole week of reinforcement of nice things we can do, kind things that we can do, that are tangible things. They are different ways to encourage and be nice to the different people in our lives.”

The week of kindness is an extension of things the school is doing already.

For instance, Hoyt reads over the loudspeaker each day a page from the book “Bucket Filling from A to Z,” which stresses the importance of being nice to one another by showing that you can fill up another person’s “bucket” through kindness and encouragement.

“We like to have practical ways to show and help kids understand that everyone likes to be around someone that is nice,” Hoyt said. “Having those actual tangible ways is an important thing to teach.”

This is the second year Northside has held a week of kindness in conjunction with the national Great Kindness Challenge campaign.

A parent pitched the idea to Hoyt a year ago and he thought it would work well.

“It was all stimulated by a parent with a great idea,” he said. “We made it happen and we will continue to do it.”

The Great Kindness Challenge, put on by Kids for Peace, Inc., is a week devoted to performing as many acts of kindness as possible.

For more information, visit greatkindnesschallenge.org.