I would write out the brain breaks on little slips in a bucket, so if the kids are getting restless or sleepy, we can stop and pick a brain break. This gives the students a minute to change their pace, posture, etc. The end goal is for them to, hopefully
Whole class journals..each student can write in them on a certain topic and the class can read them at different time. Great 'I'm finished early' activity & Great for the writing center! Also for daily 5!