Sixty-eight students gathered at DeMello Elementary on Tuesday to play with science... sort of.

“Only 25 percent of what we did here was science,” said Michael Bergen, a Bill Nye look-alike from the nonprofit Top Secret Science and Math.

For $5 per child, Bergen led the group through seven experiments, including how to make an optical illusion with rolled up construction paper and how to knot a string without letting go of each end.

“It’s mostly about having fun and building rapport with people,” Bergen said about the 90-minute session, adding that families don’t often have time to hang out together for these kinds of activities.

Alyson Doherty—mom to fifth-grader Mason and third-grader Lillian—agreed. “They go to school here and it’s something fun to do,” she said.

Not everyone immediately recognized the value of Family Science Night. “At first she dragged me here,” said fourth-grader Jay Heller, glancing at his mother across the table. “But now, it’s been really fun,” he said. His favorite experiment involved pouring silicone over sand to make it waterproof.

“When you squeeze it, it doesn’t dissolve,” said third-grader Colin Kelly about his Ziploc full of blue fluff. The instant snow comes in a can that can be bought at craft stores. “It’s similar to the powder in a baby diaper,” Bergen revealed afterwards.

Bergen has 1,500 experiments in his repertoire, he said. “We go all over New England. We work with 1,200 kids a week.”

At the end of the night, students filed out with their jelly marbles—beads that grow with 30-minutes of soaking and are great for watering plants, while parents thanked principal Cathy Maccini.

“Everyone’s happy and seems to have had a nice time,” said Maccini.