Team Sweet and Sour Sea Lions, including Sebastian Fernandez, Trevor Richardson, Maddie Graboske, Kennedy Roller and Anna Marie McIntosh, work hard to prepare more than 300 cups of lemonade during Alex's Lemonade Stand to benefit childhood cancer at El Morro School on Wednesday. (Don Leach, Coastline Pilot / March 13, 2013)

The line for a cup of lemonade stretched 100 yards from the patio to the field at El Morro Elementary School Wednesday.

Students in Jenny Carlson's afterschool business club served up the refreshment to classmates during lunch to raise money for Alex's Lemonade Stand, an organization dedicated to finding a cure for pediatric cancer.

Carlson took the money from customers as students filled cups with lemonade, a mixture of powdered mix, lemon juice and water. Each cup cost 75 cents.

"It was way too sour [without the powdered mix], and a lot of kids like it sweet," said fifth-grader Maddie Graboske. The club has met once per week since January and is composed of third-, fourth- and fifth-graders including Eric Wagner, Eli Martinez, Sophia Vandertoll, Maddie, Eliana Martini, Kennedy Roller, Trevor Richardson, Annamarie McIntosh, Sebastian Fernandez and Emma Bernstein.

They wore T-shirts with a logo of a sea lion (the school mascot) holding a glass of lemonade. Annamarie's father, Steve McIntosh, helped create the design and watched as the students served classmates.

"They told me what they wanted," McIntosh said.

The first wave of customers were first-, second- and third-graders. Teachers told them to eat first, then head for the lemonade.

"I need help making sure kids stay in the proper line," Carlson told the class, standing behind the serving table. The children placed a lemon slice on the rim of every cup.

Kennedy stood near the cash register to pace the line. Annamarie said she helped the line move.

"I kept them moving like a traffic cop in town," Annamarie said. El Morro Principal Chris Duddy estimated that 300 to 400 kids stood in line for a drink.

The lemonade stand is the club's culminating event for what they've learned thus far. Carlson said the stand combines entrepreneurship with "doing good." Students researched businesses and developed a mission statement.

They learned what to do and what not to do.

"Don't charge too high for something," Kennedy said.

Eliana thanked classmates for their purchases.

"We've learned about working together," she said.

Carlson said the stand generated $250 in profit after costs.

All proceeds will go to Alex's Lemonade Stand named for Alexandra Scott, who died in 2004 at age 8 from neuroblastoma, a type of pediatric cancer. Since 2000, Alex's Lemonade Stand Foundation has raised more than $60 million for childhood cancer research and supporting families of children receiving treatment.

Bryce.alderton@latimes.com

Twitter: @AldertonBryce