I used this site, Explorelearning, with a 7th grader with Aspergers who tested at a 1st grade math and reading level. We used the Photo Synthesis Lab (screen shot below) to gather experimental data on the hypothesis “what helps flowers grow?” He won at the school level and went on to district competition.
(As of April 2020 you can get free 60 day unlimited access.)
I once had a 7th grade student with asperger’s who tested at a 1st grade or kindergarten reading and math level. I helped guide him through his science fair project. I asked him what he was interested in. He replied “growing flowers.” I asked what helps make flowers grow. He responded with water and sunlight. From there I guided him and asked leading questions for his project on photosynthesis. He collected real data and supported his hypothesis. By the end he could explain the process of photosynthesis. This is his project board and he won at the school level and went to the district competition! This is perhaps my most rewarding experience as a teacher.