Update: How mastery percentage is calculated

If I have to be honest, I prefer the old system. It motivated users to master the skills instead of just getting proficient on them, as getting only proficient on everything only got you up to 80%. After all, mastery is supposed to be about spaced repetition; it's supposed to test how well the knowledge stuck with you. Other than that, it was also more gradual and created a more of a feeling of progression. But that's just my opinion; I'm interested in what others think of this :)

It seems to follow the level bar logic, it's consistent on that, even if we don't have a good way to see total mastery progress in classic khan academy yet

I noticed this change. I had to mentally adjust from /80 to /100, because I don't aim for mastery on my grinding account. I agree with what Xyz Y said about it.

I agree that the old system gave a stronger sense of progression. Having Proficient and Mastered count the same makes the percentage simpler, but it also removes some of the motivation to go the extra step toward Mastery.

As a teacher and tutor who has spent literally thousands of hours on Khan Academy with students (whole class, small group, and especially one-on-one), this is a HUGE (though subtle) loss for Khan Academy, as being able to get the same skill correct 4, 5, or even 7 times in a row is VASTLY different than being able to get the skill correct when asked to use that skill in a mixed-skill setting (Unit Test or Course Challenge). Mastery is a FAR HIGHER degree of learning achievement than Proficiency, and my thousands of hours of experience on Khan Academy over the past 15+ years has proven this to be true.