The reason I chose proportions was because I believe they are easy to learn. My math teacher doesn't just teach out of the book she also compare each problem to something. If you don't understand proportions go to your math teacher.
This is the way I learned about proportions. My example: 4 over 6 and 6 over 9 If 4 and 9 is multiplied it will equal 36. Then multiply 6 and 6 you should get 36. If both of them have the same product the ratios make a proportion.