Without a doubt, adding rational expressions is one of the most difficult topics in algebra 1. As a teacher I could spend weeks on it and students would mess up over and over to the point where I did not want to teach this topic anymore. What I have found is that if you can introduce it slowly, building on previous learning, using the first two pages of this set of handouts on two different days when you are teaching either simplifying rational expressions, multiplying or dividing rational expressions, then the first day of adding and rational expressions will go much smoother. The first page has 21 problems where a fraction is given and they are to find the new numerator when given the new denominator. Its all about finding what is being multiplied to the denominator and multiplying that in the numerator as well to get equivalent fractions. They get harder as the numbers increase, so you might want to go over every other problem with them in class and then allow them to do the rest independently. The second page is about determining the least common denominator: factoring and then using each factor, the highest power seen. Students will find both of these handouts to be very taxing on their brains so once again I do not recommend trying to tackle all 4 pages in one day. The third and fourth page are intended for the first day of adding rational expressions, can be used together, and provide a three step process to find the answer There is a lot of writing involved, but the handout helps them to organize their thoughts. The hope is that after the 5 guided practice problems they can do much of the work in their head on future problems, but some students will have to show a lot of work every time. I would copy these two pages on colored paper so they can find it quickly to help them the following days in class, it will cut down on the number of times you have to answer some questions. The first 4 pages are the handouts for students. The last four pages are the worked out answers for you. Start subtracting rational expressions the next day and then I recommend a comprehensive assignment the following day to see if they can perform all these operations without confusing the rules.