By some measures, Sal Khan is the most influential math teacher in U.S. history.

The 46-year-old entrepreneur and former financial analyst is the founder of Khan Academy, a nonprofit site offering thousands of free video lessons on a range of K-12 subjects. Since its beginnings as a YouTube channel (which itself grew out of Khan’s early efforts to tutor his niece in math), the organization has blossomed into an internationally known learning tool reaching tens of millions students in over 100 countries. Among its English-speaking users, Khan’s gently probing voice has become the soundtrack to their efforts to learn algebra or geometry.

The organization’s mission grew during the pandemic, as traffic to the website surged amid widespread school closures. User minutes on the site grew steadily in 2020 while American students were largely learning in isolation from teachers and peers, and for a time, school systems across the country were attempting to recreate Khan Academy’s model on the fly.

Their efforts, while often heroic, were insufficient. Reams of COVID-era research have shown conclusively that remote instruction led to disastrous learning losses in foundational subjects, with particularly steep declines in math skills. And even after two years of doleful news about schools and learning, October’s release of NAEP results still managed to shock education observers.

The federal test, often called the “Nation’s Report Card,” showed that fourth and eighth graders both sustained unprecedented drops in math performance. The damage to older students was especially severe, with 38 percent of eighth graders scoring below the exam’s lowest level of proficiency during the 2021–22 school year. While the worst of the pandemic-related learning disruptions is behind us, a long climb remains ahead.

In an interview with The 74, Khan said that learning recovery can’t stop with a return to the pre-pandemic norm, which saw huge numbers of students ill-prepared for college and bound for frustrating bouts with remedial coursework. He believes that American math education should be more organized around the principles of “mastery learning,” a pedagogical strategy that focuses heavily on providing pupils the necessary support to address their existing knowledge gaps before moving on to new material.

Read the full article about COVID's impact on math scores by Kevin Mahnken at The 74.