Additional Added Exercises

Hi Alexa,

Adding new exercises usually drops percentages unless they are not new math skills. KA added many new skills recently, dropping percentages because of a greater denominator. This article might help:

https://khanacademy.zendesk.com/hc/en-us/articles/115007408888-New-exercises-coming-to-missions-July-2017

Jett, thank you for your supporting documentation.  The information was understood previously.  

I still believe completed missions should remain completed.  Another way to look at this might be for you to ponder your own situation. What if you learned tomorrow that the degree you completed years ago was no longer completed/valid because of additionally required coursework?  That previously earned, but now incomplete degree which helped you gain your current position requires you to return to your university for completion.  Probably not one of your priorities.

Changes to a curriculum/mission in progress is understood as those changes do not rescind a completed course or courses.