I cannot master a unit even whith Unit Test passed at 100%

Try this: Check if all your practice got mastered. If your practice is not mastered, your course could not be completed. OR If it says proficient, it is a case where you need to take the unit test one more time. And take the test until ALL of your practice got mastered.

Hi Juan,

In this situation, you'll have to take the Unit Test in order to achieve 100% mastery, since that is the only way to level up a skill to the "Mastered" level.

In larger units, there's not enough questions on the Unit Test to cover all of the skills, so you may have to take the Unit Test more than once in order to master all skills in these units. This is done to prevent the Unit Test from being excessively long in larger units.

I hope this helps! Please let me know if you have any additional questions!

Thanks. 

That was it.  I understand now the comment

"If you are interested in achieving 100% Mastery, you can take the Unit test again."

The system is a bit confusing. Also, since topics in the different takes of the unit tests are likelu to be repeated, it becomes more difficult to master the unit (i.e. more risk of making silly mistakes). I would rather have 2 Unit Tests, for instance.

But at least now I understand the problem ;-)

Evan Lewis

Honestly, this is kind of annoying. I have to redo the entire Test again just because of a silly mistake, miss input, or even if it was an honest mistake in order to achieve Mastery.

Would be cool if there was an option to get mastery by taking some sort of Test after completing a Unit Test that goes over the topic you made a mistake in only, instead of having to do everything all over again, opening up potential to make a silly little mistake in another area of a topic, and then you do that same test multiple times, even though you know what you're doing. 

It may be practice, still. But it's super frustrating when you know that you messed up the test and have to take the whole thing again for the mastery, halfway or almost at the end of the Test.

Thanks for the feedback, goeggig! I definitely understand how that can be frustrating.

We've actually introduced something similar to what you've described, but only for the practice exercises currently. The Unit Tests still have the "Start Over" feature, but not the new bonus questions. You can read the announcement here: https://support.khanacademy.org/hc/en-us/community/posts/36008745490317-Update-Introducing-bonus-questions

I encourage you to post in that thread about wanting this for the Unit Tests.

I got proficient in the lessons and then took the unit test. After getting a 90, I realized it didn't give me the mastered indication. It said that some lessons weren't tested and that I needed to take it again to get mastered. I took it again, got a 90 and nothing changed. KA wont let me master the unit.