By CAMILLE PHILLIPS, St. Louis Public Radio

Two weeks before the new school year, St. Louis Public School teachers Ninfa Matiase, LaJuana Stidmon and Jeremy Resmann cut red agar into squares before dropping them into vinegar. It’s an experiment to test how quickly the cubes absorb the vinegar — one of several lesson plans the teachers have learned over the past two weeks during training provided by the National Math and Science Initiative.

Stidmon, a science teacher at Clyde C. Miller Career Academy, says the training has given her a framework to focus her AP biology class.

“It made me feel like I can actually do this and I can actually prepare them for getting a qualifying score on the AP exam. When other times it was like I’m flying by the seat of my pants,” she said, adding that the training was a good follow-up to recent increases in the number of AP classes offered by her district.

The National Math and Science Initiative offered the training as part of a three-year program to increase the number of high schoolers who pass Advanced Placement exams. The program also funds weekend tutoring, offers stipends for AP exam fees and gives both students and teachers $100 for every AP exam with a passing grade.

St. Louis is one of nine school districts participating in the program nationwide. It’s funded through a $20 million grant from the U.S. Department of Education.

Former St. Louis Public Schools middle-school teacher Stephanie Markman is the grant program manager for the National Math and Science Initiative. That connection is one reason the district was chosen to participate.

“I thought that this would be a great place for us to do this work, and the students here obviously deserve it. And it’s great to know that students I taught will get opportunities that they might not have had previously,” Markman said.

Markman said St. Louis Public Schools also fit her organization’s goal of reducing racial disparity in AP exam participation.

“We want to ensure that teachers have the tools to teach all of their students at a rigorous level to make sure that they are college and career ready. That’s really the larger goal.”

Overall, the program aims to more than double the number of AP exams with passing scores in participating schools by the time the program ends in 2019.

After going through an application process, the National Math and Science Initiative selected six St. Louis high schools to participate in the three-year program: Central Visual and Performing Arts, Soldan International Studies, Clyde C. Miller, Collegiate School of Medicine and Bioscience, McKinley Classical Leadership, and Metro Academic and Classical.

All six schools are choice high schools, with an application process required for students to enroll.