I found the SRA placement tests online. They have one for comprehension and one for decoding.
DS has continued to complete all of his works daily since we started the incentive "program". He even had a meltdown free day yesterday.
I got a little clarification on the meltdowns at school, and ds had another counseling session yesterday. When he has an actual meltdown, it's ALWAYS related to perfectionism or avoiding boring or un-challenging work. The other "outbursts" that the teacher would like to get under control have to do with ds raising his voice and getting upset at other students. Usually, his reaction doesn't match the situation. In other words, he overreacts and takes things personally that he probably should be able to blow off.
DS and I have been discussing ways to avoid these conflicts. One issue is that he worries too much about what other kids are doing. I've told him he is to worry about his own work and forget about what other students are doing. He's in everyone else's business too much, and then he doesn't understand why they get upset with him.
For example, he corrected a 1st grader for scribbling all over his paper. The kid told him he could do what he wanted, and ds got upset b/c the kid wouldn't listen and follow the rules. When ds started Montessori, it was ok for other students to correct him, and he didn't like it. Now it's his turn to "help" the younger first graders, but evidently he's not taking a nurturing approach! ; )
So, I told him to forget about helping the others for now and just worry about his own work.
The teacher actually said yesterday was the best day he's ever had. DS seemed a bit perplexed by this; to him it was just a good day. Also, ds was happy about the day because not only did he finish all of his work, he even asked to do a 3rd grade work. He didn't know it was a 3rd grade work until he'd completed it; it was just something that interested him (homonyms). He is really into language. You should hear the "explanations" he comes up with to explain English words that do not follow phonetic rules. It's so funny how he will invent a spelling or grammar rule just to restore the order and pattern he is looking for! He can't accept that some words just don't follow the rules.
The counselor says he has no doubt that the "meltdowns" are really anxiety attacks. He spent some time with ds teaching him relaxation techniques, and they did some guided imagery, which ds loved. I am hoping we can help him handle the anxiety without medication. For now, we're going to stick with the counseling and see how it goes.
Thanks again everyone!