I have finally gotten the right fonts on my home computer so I am able to share some of the resources I have created for use with students with ASD and/or an intellectual impairment.
I have posted two resources today that are actually used together. First is a story explaining how to do two digit addition with concrete materials. The second is the resource to make the boards used in the story.
http://www.scribd.com/doc/68555647/2-Digit-Addition-Story
http://www.scribd.com/doc/68549143
I had great success teaching this way. The student with (extreme) ASD became very focused when there was a story involved. My inspiration was all the social stories that I had written for her, and so I thought teaching maths concepts through stories would work well too.
For students with an intellectual impairment, it forced me to break the task into small pieces and because I was reading the story, I would not forget each of the little pieces. I always use photos where I can in stories so that the students can identify exactly what I am saying.