I wish there was a little bit more data on this last chart. How are they measuring 'math progress' here? It looks like the data comes from "online usage data from Zearn math", but how is progress being measured? Does a +53% increase mean that average classroom scores (tests and quizzes?) increased by 53% over where they were before covid? Does it mean the class as a whole covered 53% more of the topics than they would have otherwise? It's unclear to me.

Whatever the measurement, I find it just as interesting that there was such a large increase over pre-covid for the high income zipcodes. My assumption would have been a decrease in the low-income zipcodes (due to access to technology resources for e-learning, more friction in adjusting to staying at home, economic woes effecting low income families more, etc), but the high-income zipcodes to stay roughly the same. It looks like (for math at least) that e-learning is working out great when you have access to the technology, much better than regular in-person school (assuming what they're measuring as 'progress' is actually meaningful to begin with).