– The Chess Lady cheerfully explained the Fibonacci sequence to a group of third-graders at Dewey Elementary in Englewood, Ill.

“Add the first two numbers to get the next number,” she said via video, after the pattern “1, 1, 2, 3, 5, 8, 13, 21” appeared on a screen at the front of the classroom.

Later, at a chess event, one third-grader couldn’t believe she was listening to the actual Chess Lady. “I cried when I saw her,” she gushed. “I actually touched her, and I was shaking.”

Demetria Vaughn was one of 300 Chicago Public Schools students who spent a day at Guaranteed Rate Field for a chess extravaganza — chess arts and crafts, 10 stations of chess lessons and, the piece de resistance, the Chess Lady.

The students in attendance all take part in First Move Chess, a national program that offers chess curriculum to second- and third-graders as a way to introduce them to the game and help them hone the critical thinking, math, sportsmanship and social skills that go along with it.

CPS has been partnering with First Move for five years, and the program is actively used in nearly 100 schools this year, said Nichole Matthews, CPS academic competition coordinator.

“I’ve seen chess break down so many barriers,” Matthews said. “You’re learning the curriculum, you’re learning math, you’re learning history, you’re learning social skills, all while moving pieces around a board.”

Friday’s event was a year-end celebration for students from three schools who had just completed a year of First Move learning: Mariano Azuela Elementary in Little Village, Pulaski International School in Bucktown and Dewey Elementary.

The students each received a passport upon arrival. When they had visited all 10 chess stations and mastered the lessons therein, they were pointed toward an 11th station to receive a medal from none other than the Chess Lady, whom, before that, they had only seen on a screen in instructional videos.

“I was screaming, and I gave her a hug because I didn’t even know she was real,” said Niciah Washington, a Dewey third-grader. “I thought she might be a fake person. Some people, you see them on YouTube, but they’re not real. But she got on the microphone, and it sounded just like her. I think it’s really her.”

The Chess Lady takes her fame in stride.

“One of the wonderful things about this program is, as you see, they truly are excited about chess,” she said. “They’re excited to see me because they’re excited about chess.”

As is she.

“It’s learning to shake hands before a game,” she said. “It’s critical thinking. It’s learning to play fair. It’s math. I had a child one time say to me, ‘It’s really sneaky learning.’ ”

The students agree.

As they huddled around desks, strategizing and collaborating, their teacher Paige Watkins walked them through the chess lessons using the videos, workbooks and playing boards provided by First Move. (Matthews said First Move normally charges schools a nominal fee for the materials, but it has waived the cost for CPS.)

“Chess is a calm-down game,” third-grader Kenneth Sims said. “It’s not a game you rush through. It’s a thinking game. When you feel like having a temper tantrum, chess calms you down.”

Fellow third-grader Khamaria Hudson said chess has improved her reading.

“It helps me focus and go slow,” she said.

“It doesn’t matter whether you’re big or small, rich or poor, black, white or polka-dotted,” the Chess Lady said. “Chess levels the field. I have teachers who say, ‘I’ve got kids who are playing together who don’t normally play together. They’ve got respect for each other on the chess board.’ And because we teach it in the classroom, rather than an after-school setting that might be more competitive, you see them help each other. ‘You know what? You don’t want to make that move because then I’ll be able to capture you.’ ”