For a long time, I wanted to create a series of workbooks that would be effective teaching tools for students with Autism. When I found Kumon workbooks, I realized I didn't have to! These workbooks are high-quality and full-color, which makes them look interesting to children. But, more importantly, they present learning activities in very small steps, similar to the ABA method of shaping.
Since some students with autism require more repitition of a skill, what I do is purchase the workbooks and laminate the pages. You can then write on them with a dry-erase marker, so they can be used over and over again. This can be your practice copy of the workbook. Purchase another copy of each workbook for the students complete on their own after they've practiced. This will give them a copy to take home.
Note: Don't worry too much about the Kumon recommended ages for each book. I think sometimes they are a little bit low. I use the books with kids who are older than the specified age ranges if those are the skills they need to work on.