Homeschool Math Program for ASD child?

[Guest guest]

My son had been doing great in math. He is 9 and was adding, regrouping, and

subtracting up to 3 digit numbers all last year. Then we did a long unit on

time and money. 2 weeks ago, we went back to adding as review and it seems he

doesn't remember a thing. This kid never forgets anything, but suddenly he

can't or won't add. Today all of his answers were the letter " H " . We are back

to 1st grade stuff now--1+1 and it seems he cannot even do that. I guess I'm

going to have to start from scratch. We have been using simple Harcourt Family

Learning Math Skills workbooks. I enlarge everything and if the pages are too

cluttered, I hand-write problems so he can write large. I draw boxes for his

answers so he knows where to write. I make review worksheets when he needs

extra practice (that's why we spent so long on time and money.) Reading has

always been his weak point and math was always a breeze. I don't know where his

math has gone. I just keep trying and hope it will come back. Anyone

homeschooling? What programs have worked for your child?