I have a brief update for anyone interested in our story.
This summer we did work a lot on estimating passage of time. It really has helped! I bought the TimeTimer (visual representation of time passing) and used to when my son got on the computer or TV to measure his 30 minutes of screen time. We also used it at the pool this summer for the 15 minutes of Adult Swim. Just these two things alone seem to have improved my son's ability to understand how long 15 minues and 30 minutes are.
In addition we got a GPS for the car. My son has been using the GPS to monitor where we are going and how much longer the trip will take. In the past doing even short errands with im has been very frustrating, as he'd get in the car and start complaining almost immediately about how long everything was taking. I now see that he really had no sense of the difference between 10 minutes in the car and two hours!
How this translates to homework -- he;s in 4th grade now and the HW has hit us like a ton of bricks. I'm having him look at each assignment and estimate how much time he thinks each one will take. At first he would be overly optimistic and say "Just a math worksheet, that's 5 minutes" but over time (and we keep records!) he sees that certain types of worksheets take 10 to 15 minutes, reading worksheets might take 10 minutes per page, etc. So he has a much more realistic sense at the start of how long HW will take, which helps overall.
