Thanks everyone for the input. Dd just also received her invitation for the NUMATS ceremony. I think what I'll do is tell the twins that they have been invited to the state ceremony and let them choose whether to attend or not. Since dd made the cut for the NUMATS ceremony and ds did not, I think we'll definitely skip that one.

I still feel uncomfortable about attending -- it would be one thing if the ceremony involved achievement based on significant effort on their part. But in this case all they did was show up for a test I signed them up for. It wasn't even their idea. I fear that making a big deal out of it will some how send the wrong message about our expectations for them. So when I ask if they want to go, I guess I'll be up front about that.