The Derivatives: definition and basic rules is a section of Differential Calculus on Khan Academy that has a 25 question unit test. Not being able to reset a test like this when most mistakes that those capable of reaching 100% make are simple mistakes of formatting in their answers makes achieving 100% very time consuming and frustrating. Please add a reset button for unit tests at least. This one has 25 questions. When you make a simple mistake not even half way in the test and have to finish it completely before giving it another try, it can become very annoying and stressful. I do no understand the argument that it allows students to dodge having to practice a certain skill since students like that won't even reach 100% even with a reset button. However, I do agree that it makes us less prone to making mistakes in the future, although that doesn't make such an impact since almost every mistake is a mistake in formatting, and not comprehension of the subject. This results in time wasted.
I know there is already a post about it (which I up voted), but I simply wanted to express my opinion since this matter has been going on for at least 4 months without a concrete response from Khan Academy support on the matter.
Khan Academy is an amazing platform, but, not being able to reset a unit test wastes time for many students... Time that could be spent studying new subjects instead.