In one room, the Explorer K-8 fourth-graders were determining the amount of freshwater, as opposed to saltwater, on Earth.
In another, a group was finding out how long a soda can tossed into saltwater would last. (Answer: 200 years.)
The students were visiting the Springs Coast Environmental Education Center on the Weeki Wachee River for a day of science.
The two groups took turns with center director Cheryl Paradis and staff member Jessica Ballew learning about water, the aquifer, the water cycle and Florida wildlife.
In one activity, Paradis held up a large graduated cylinder full of water, representing all the water in the world. She asked the children how much of it represented drinkable, accessible freshwater. They pointed to various fractions of the cylinder, averaging about one third of it.
Paradis poured 28 milliliters of the 1,000-ml cylinder to illustrate all of the freshwater in the world. Twenty milliliters of that represented ice. She continued reducing the amount, showing amounts of polluted water and inaccessible water. She ended the demonstration with a single drop, representing the water we drink.
In Ballew's classroom, students, their teachers and chaperones scurried around the room, earning chips by finding answers to questions about the water cycle, the watershed and other water-related subjects.
"How is the water cycle powered?" (Answer: By the sun.)
Paradis took her students outdoors to see the water-collecting barrels she uses to water the garden in the front of the center.
The barrels were partly covered with the signatures of students who had visited the center in the past and taken a pledge to conserve water. She invited these groups to take the pledge and sign the barrels, too.
In still another classroom, the groups took turns doing a habitat hunt.
Paradis has taxidermies including a black bear, a coyote, a whitetail fawn, a bobcat, an eastern diamondback rattlesnake, a gray fox, an armadillo, sand hill cranes, an opossum, an otter, a limpkin, a great blue heron, a raccoon, a barred owl and a red-shouldered hawk.
There were also live animals: an eastern fence lizard, a green anole and a five-lined skink. Nearby was a display of various furs that the children were allowed to touch.
They were given questions about the critters in the room and turned loose to go from creature to creature to answer them.
"We're teaching about the food chain in this room," Ballew said.
The animal room seemed to be popular with the students. Zahra Rognstad, 10, said, "I liked to pet the fur and look at the animals."
"I loved petting the bobcat fur," Gwenivere Bankey, 9, said. "It's so soft."
Alexia Hopkins, 9, said she enjoyed everything about the environmental center.
"I actually liked experiencing the place," she said.