She admitted she did not always like math.
"I sat in seventh-grade math and had an amazing teacher, but I was so stressed and had so many troubles understanding it, and I always tell (my students) I don't want them to feel that frustration," Mason said.
When a high school coach offered to tutor her in geometry, she said she began running.
"I couldn't imagine sweating or athletics then, but he helped me, and helped me pass," said Mason, who last fall coached her alma mater's state championship cross country team.
Thirteen-year-old Matt Henry said he is learning to like math.
"Yeah, she's great because I used to hate math, but she's taught me that you have fun and learn," he said.
Students moved from one cluster of desks to another working out problems in small groups Monday. A "game plan" at the front of the baseball-themed room - Mason is a diehard Baltimore Orioles and Hagerstown Suns fan - included warm-up and cool-down activities and a visit from a special visitor - Norma.
As students returned to their regular seats to go over their work, Mason chose a "guest teacher" to take over the front of the room. Flailing her arms, Mason ran toward a desk and let out a "Woowhoo!"
Norma had arrived.
The teacher's alter-ego, Norma was conceived during Mason's second year to create some excitement during routine tasks such as homework reviews, her creator said.
While the spelling of her last name - Nunyua for none of your business - is a variable, Norma herself is typical of some seventh-graders - high-energy, low-focus and disruptive, Mason said.
Assistant principal Barbara Fromer, who last week entered the class right after "Norma" had kicked over a desk, said Monday she is impressed with the teacher's creativity and ability to connect with students.
"She's an excellent teacher," Fromer said. "She's very creative. Children are just always right with her."
For Mason, 28, having fun just goes with the job.
"It's fun," Mason said. "I get to goof off with kids all day, and they pay me."
During one recent class observation, Fromer said she watched as Mason and students discussed percentages and decimals using examples from baseball.
"And, she was pitching to a student who was hitting the ball, and then they were figuring out the percentages of the chances the student would hit the ball," Fromer said.
Mason said she always is looking for ways to help students understand without the tears of frustration that accompanied her early math experiences.
Though Mason's classroom repertoire now includes baseball board games, group work, batting practice and songs about math concepts, she acknowledged Monday she still is trying to figure out her own teacher's secrets.
"I don't know, I really don't know how he did what he did," she said. "I guess I'll spend my whole career trying to do the same thing."