Thanks Colinsmum, the 'are you ready for this?' sounds like a good resource, I will check it out.
I am not trying to figure out a placement at this point; I do give him some instruction for most of the pages, usually just 1 or 2 examples and then he does a handful of problems based on what I've shown him. I am definitely not expecting him to handle the same unaided in a classroom, at least not the hardest ones, so perhaps I will add this to my note I will be sending along with the work examples.

https://twitter.com/asimom, https://contributingfactor.wordpress.com