You might consider trying CLE.
I just had a look at this. I'm not in the US so I think postage costs would make this fairly expensive to try. I couldn't see a digital option, or any international distributors. I've seen quite a few people here say they like this maths though, so might dig a bit deeper.
If he does well with cubes, MUS comes to mind. It combines hands on work with worksheets and definitely uses the mastery approach.
Another one to consider might be RightStart. Instead of blocks, it uses an abacus, along with other manipulatives and games--and it has worksheets too.
Finally, Singapore is also hands on, if you follow the HIG. And it has worksheets.
I am worried about MUS - is it too 'light'? Too different from other curricula in scope and sequence?
I think Right Start would probably be my top pick at the moment. But.....it is ridiculously expensive even without international shipping. If I had a guarantee that it was going to help, this would be my top choice, but so much money would be wasted if he hates it. Can't decide if it's worth the risk.
I don't like grade 1 of Singapore. I used it with my oldest (accelerated in math) kid, and we ditched it for a bit, then took it up again a bit later. Maybe I could teach it better now though?? I've got 8 years more experience in teaching first grade maths after all!
HOW did he use MM1? Were you with him the majority of the time, reading the lessons with/to him and leading the lessons?
I've used every chapter of MM1-7 with my kids. A big part of what made it successful was my close interaction and engagement with them as they used the book. It is a work text, but having an adult keeping things on track and answering questions immediately and correcting mistakes real time is what made the program effective.
Yes, I have sat with him and done each and every lesson with him. I don't really want to go back and do it over again for a couple of reasons - 1. I just think he hates it now and it is torture for him and 2. My 4 year old has already started it, and is whizzing through it at breakneck speed - I wouldn't want my older guy to feel sad that he is doing the same thing as his little brother.
I would get c-rods and use gattegno math. The first books are floating around online for free so you can try it out before investing. There are videos on YouTube, too, showing how it is used in a classroom.
Never heard of this....off to look it up. We have c-rods already.
Thanks so much everybody. Always such good advice