You can get extra credit for five test problems that you missed points on (any test).
Five problems maximum.
Do the part of the problem that you missed originally.
You’ll get two points per problem or three points if you missed half or more of the points for the problem. (You can even do things like missing factors of 10).
Also, if you would like to replace your lowest test score with the score from the final, the requirement will be that the class has a total of 50,000 points on Khan Academy for everyone to have the option. Right now the class has 17,643 points. I personally have 14,091 points, so that should be reasonable. If the class doesn’t reach 50,000 points, you can still get the option if you personally reach 10,000 points.
I would suggest trying some of the math exercises on things like natural logarithms, exponents, and other things related to the class. As well as viewing videos on topics we’re covering.