For Kindergarten

For Kindergarten we read tons of books, did BrainQuest cards, Leap Pad, Jumpstart Kindergarten, watched Read Between the Lions on PBS, did map puzzles, played Monopoly Jr., baked (he would measure everything), did writing on a dry erase board, played store with a toy cash register and real money, etc. I just focused on fun learning. If you need to give some kind of a log or record to your ex, I would not list the actual activities above--just write what subjects you cover with the activities:

Math

Language Arts

Reading

Geography

Science

For science we would look online and make a volcano or observe a black widow in the garage (Enchanted Learning has awesome labeled coloring sheets), go on a hike and look for lizards, play with magnets, a compass, make static electricity with balloons, etc. I bought two kitchen science project books from the Parent Teacher store--fun and easy!

You can do this! Your son will be so happy and love this and you won't be so stressed out. Don't get too caught up in having to follow some formal advanced curriculum to satisfy your ex. Once you get your son to the point where he loves learning, gradually introduce FUN work sheets from online (my ds despises workbooks-- finds them boring and repetitive). There are curricula out there that don't focus on seatwork.

If you are worried about keeping your ds at grade level, you might find your state's education standards online--my state lists all subjects and standards by grade.

Enjoy Childhood

It is time to enjoy childhood, not cram for the SAT's - not that I am suggesting that you are doing that.

We only get to be kids once so have fun with it

We only get to be kids once so have fun with it.  If he's not into igloos, drop it and try something else. But don't tell him it’s a 'lesson'.  Just do something for fun.  Have a contest, whose ice cube will melt faster, yours in a glass of soda or his in an extra hot cup of cocoa. .  Try something like that.