I think you could also have multiple pipe cleaners coming from one number and students have to show multiple ways to add numbers to get to that number. Counting with pipe cleaners and beads. Great for fine motor development too.
With ASD passive social comprehension is affected very much, too, not just active participation in social action. A big part of it can be described as "context blindness" (Donnah Williams) And it is not just in direct interaction, but also in the written.