After going through this packet you should be able to solve proportions using cross products.
You will learn how to solve simple proportions and more complex proportions. You will also learn to set up proportions when using similar figures.
http://www.arcademicskillbuilders.com/games/dirt-bike-proportions/dirt-bike-proportions.html
This game doesn't have the hardest proportions to solve, but it does help with speed.