HARLINGEN — The two girls engaged in a sort of medieval duel using 21st century technology.

Aliyah Saucedo and Giselle Gonzalez, both 17, had just attached coil cell batteries to small colorful wands. They now slugged it out in the middle of the library at Harlingen High School South.

“It’s like a little light saber,” said Aliyah, who was dressed in her cheerleader uniform and volunteering Saturday at the school’s Community Code Jam. Harlingen South hosted the hands-on computer science experience with different tables labeled for such sessions as “Costume Change,” “Guess the Number” and “Unplugged.”

“Basically, we have different sessions and they are all related to STEM and computational thinking,” said Edmundo Lopez, computer information technology/robotics instructor.

“It helps students solve problems and investigate and encourage inquisitive minds,” he said.

The kids gathered around the tables seemed to enjoy themselves.

“It’s going pretty good,” said Omar Lerma, 17, who sat at the table labeled “unplugged.”

He and the other students had colorful paper figures in front of them.

“We are making origami,” he said. “It looks like a butterfly but it’s a lady bug.”

So how does an origami lady bug become a STEM activity? Well, how about a little animation with a coil cell battery?

“That kind of makes it flutter,” said Matthew Leija, 17, a senior who was volunteering for the event.

Aliyah was enjoying the afternoon helping out with the different events.

“I am pretty happy some people showed up,” she said. “This is really interesting. I think a lot of people should know about this.”

Giselle agreed.

“I think it’s super fun,” she said, looking at her light saber.

“I never thought that we could do that with simple stuff,” she said.

Librarian Betsy Vela said another event like this would probably be held in the spring.

“We look forward to seeing more people come to our event,” she said.

The activities definitely filled a need.

“A lot of them have never experienced this,” Lopez said.

Leija nodded in agreement.

“A lot of them don’t even know negative and positive,” he said.