Melissa Graff, 9, may look like she's just playing with Legos, but really she's learning about structural engineering.
"If you just put them on top of each other and not cover cracks then it's going to be easy to knock over," said Graff. "You have to overlap them by covering the cracks."
The girls are building houses and bridges with the help of Play-Well Technologies instructor Briana Headley. She asks her students, "Let's see, does that go there? That could, but what do we need right there again?" The students respond with "the keystone."
Keilah, 9, is a little more focused on driving over the bridge now that she knows how a car's transmission works.
"Right now, this one's medium speed, but if we put a small gear on top and a big gear on bottom, it would go really slow," said Keilah.
"There's a side of Legos that gets much more complex and interesting, and they're great learning tools. 2001," said Headley.
There are about 170 of these weeklong summer programs all over the East Bay, but this one is a little different. You might have noticed all the kids in this classroom are girls -- girls who are having a blast with engineering.
"We took a chance. We decided to say, 'Let's create a space for girls to be who they are, and to become interested in engineering, science, robotics,'" said Georgia Rudderow with Play-Well Technologies.
Until now, teachers say most of the kids in the program were boys, but these girls are giving them a serious run for their money.
"They're very adept problem solvers, they're not so consumed by trying to make something bigger or faster, but rather is something more efficient, does it work in the way we want it to," said Headley.
And as the girls write the programs that turn the plastic gears, teachers see the gears in their heads turning too.
"What we call the a-ha moment of 'I get it!' and that's really what we live for," said Rudderow.