Hi everyone, thanks for all the responses!
It didn't even occur to me he could be a bit rusty after a nice long summer.
I will definitely check out the various suggestions on building confidence and speed with some of the cool sounding tricks and methods! Thanks guys.
Also, flowersfamily, definitely feel free to chime in anytime, I am hoping for only some advice from anyone who might be dealing with similar problems; not expecting 'expert' input
I did send the teacher a note today asking her to try, in her attempts to figure this one out, to give ds some problems to do in his head (and lots of time) because I do think he can handle more; I've seen him do harder sums in his head for fun ...but sometimes it does seem like he's literally unable to get past some invisible mental barrier!
