sitting for workbooks=mexican SJ bean

We just sat in the dining room to do SJ's workbook pages.  We needed to do 2 books today (context clues and main ideas) since we had to skip them yesterday.  First, he had to stop working to get dressed.  He had his pajamas on, but he wasn't in his clothes for the day.  I told him that he could work in his pajamas, but he was already half way up the stairs to his room.  After he came back down, I asked him if he was ready.  He said that he was and we started to read a paragraph from the context clue book.  I don't think we read more than 3 sentences and he had to stop to go to the bathroom.  I told him to go, but no more interruptions.  I told him we needed to do his work and he shouted that "he hates work".  I told him that I hated hearing him shout.  After his "bathroom break", we restarted the context clues book.  I know he has trouble sitting, but I couldn't believe how many times he got up or fidgeted in his chair.  After about 10 minutes, we had finished the first book.  He had some trouble with the context clues.  I tried to show him how to find the clues in the paragraph, but he was moving so much that I wasn't sure he was listening.  He did manage to do the last question on his own, so I guess he was listening.  He did a much better job with the main idea book.  He still was moving a lot in his chair, but he was able to do most of the main idea questions on his own.  Maybe I should invest in a wiggle seat for our house.  He has one at school and I don't think he likes it.  I can see why he needs it though.  I think he has a constant need to be in motion.