I have a 9 year old daughter that has been diagnosed ADHD and Bi-polar. We don't medicate for the Bi-Polar but she has a very hard time functioning in the PS setting which is why we homeschool. She can spend 20 minutes to 1 hour on math but I sometimes have to break up the lesson into pieces. I use Growing with Grammar so that only takes 10 minutes or less a page, Sequential Speller which takes less than 10 minutes, Wordly Wise a lesson will take us easily a whole week. My point is that I try for 20 minutes or less per subject but if she isn't focused or is having a "bad day" I break it up or leave it for another day. She likes History and Science because I make it very hands on and she likes to color and draw. Those subjects she will stay interested in for at least an hour.
I just try to keep in mind that when she was in PS she really was getting very little because the staff had to spend most of the day "managing" her. I can't compare her to other kids because she is different but I do my best as I am sure you do to. Some things we use are weighted blankets, ankle weights and wiggle seats. Those can buy right at wal-mart or target. She also likes to sit on exercise balls sometimes. We even have an inflatable bounce house we blow up in the livingroom for those days she just needs to go go go.