It might be a simple solution but I can not fix it.
I am dividing 2 integers :
finishedGameFinalScore = [score integerValue]; CGFloat interval = 2/fi
Just add the f-hint to the number 2. in this case that will do the trick.
CGFloat interval = 2.0f/finishedGameFinalScore;
all the above/below answers are correct and fully explain why this work.