ST. PETERSBURG — The four blond children huddled up to the table, their wide eyes trained on a goopy mess inside the glass jars before them. Two teenage volunteers poured in the ingredients: water, Elmer's school glue, borax, green food coloring.
"Let's mix it up," said Danielle Morris, 15, a Dixie Hollins High School student lending part of her Saturday to Great Explorations Children's Museum.
"And then it makes it slime?" asked Austin Poirier, 6, sounding a bit unsure of this "slime" business.
"Yep," Morris said.
"Can I play with it now?" Austin said.
The substance still resembled pea soup. So, no, Morris told him. Not yet.
The volunteers added more borax. Austin's cousin, Claire Hoffman, also 6, stood from her bench.
"Sugar, sugar, sugar," she said, grinning.
Her dad, Chase Hoffman, leaned over.
"That's not sugar," he said. "That's borax."
Claire, disappointed, sat back down.
"Oh," she said.
The slime station at Great Explorations was an ode to Nickelodeon, the TV network that for years has dumped the gelatinous substance on people's heads as a sort of trademark. On Saturday, Nickelodeon held its 10th annual Worldwide Day of Play.
It suspended programming for three hours, urging kids to "get up, go outside and play." Millions worldwide were expected to participate.
Great Explorations took advantage of the opportunity and offered $5 admission, and an array of special activities, all day.
Hoffman, 29, had learned of it through a family member. He said his kids don't watch much TV anyway but he appreciated Nickelodeon's efforts.
"That's admirable," he said.
On the other side of the indoor playroom, about the size of a high school gym, staff coordinator Micah Madir watched kids compete in a Hula Hoop contest as I Like to Move It pulsed through the speakers.
"I think it's terrific," he said of the TV network's initiative. "I wish more channels did that."
Saturday's promotion drew hundreds, but not everyone who showed up was even familiar with the blackout.
Amelia Fahnestock, 2, dressed in all pink and light-up shoes, pushed a miniature cart through the Publix: My First Market store, perusing plastic grapes and corn on the cob. Her mother, Zoe Rosai, watched.
She and her husband just recently moved to St. Petersburg and became members at Great Explorations. She knew nothing about the Day of Play.
"We don't really watch any TV," she said, though they do have Netflix. Amelia likes Thomas & Friends.
At a science display nearby, Julian Llanio, 4, closely examined the brain size of a bear. His mother, Natalie, visiting Great Explorations for the first time, said managing her kids' TV and electronic usage (she also has a 7- and 14-year-old) is a challenge.
She allows no video games or violent cartoons. Her teenage daughter has a carefully monitored cellphone. Llanio prohibits Facebook.
When she was young, parents insisted that kids go out and play because that was just the thing to do.
"I try," she said, "to continue that."
Times researcher Natalie Watson contributed to this report.