What about putting your child more incharge of his learning. Have him make or pick out a jounal for homeschooling. This ia also a wonderful way for them to see their progress. Then each day he writes at least a minimium of goals within a framework you two decide on together. If you go to a museum for the day attach the brochure or stickers or bring the journal to sketch.
How about a talk together about what he needs in his school plus what he would like. Maybe he wants to have a field trip once a week.

List of subjects daily and Someflexible goals

1 Math= work on addition facts, Play a math game on the computer

2 Reading - he picks the story read for X mins.

3 Writing- he pick the type of writing, a poem, thoughts on the reading, make own book,

4 Gym- go for a walk in the woods and find 10 different leaves.

5 Science - identify leaves in a book

6 Art - make a wreath with the leaves to hang on the front door.

7 something with Mom - play a game, or cook something(math here too)