I'm heading back to work next month, and my 4yo will be at home after school with our nanny. I'd like him to play a bit on the computer as reward after finishing homework.

Any suggestions for online learning games that are enjoyable enough to feel like a reward but still manage to teach/reinforce?

We've liked Prodigy, Starfall, Reading/Math Seeds, and Dreambox at various times, and I'm looking for new options. He's an independent reader, great with the mouse, and does fine with games in 1st grade math.

TIA!