To me the best closing affirmations are those given on page 51 of the 3rd edition of PhotoReading.
"I want to learn all the topics we are doing in class and be able to work out problems fluently" I think ths is a suitable affirmation... I'd like to offer a couple of minor changes if I may.
Change "I want... " to 'I intend' (has your mother ever said, 'no', when you said I want? Then, I think you can understand the reason I suggest that change.) 
Since it for class I am guessing that at some point your knowledge is going to be tested/graded for this I'd like to add... 'to obtain my best passing grade on these topics'.
So the affirmation would be...
"I intend to learn all the topics we are doing in class and be able to work out problems fluently, to obtain my best passing grade on these topics."
Alex
