How do you make homework more interesting for kids?

You make it meaningful to them. Try to find ways that the information they're trying to learn could be useful - even if you have to make it a silly reason like "You're going to need to know the countries of Asia in case you're ever kidnapped by rabid Mongols and they tell you they'll boil you alive if you dont' know them."

You can also make little puzzles and games to help them learn, or quiz them on the material.

Give small rewards for doing the work, like gold stars, and offer to trade X stars for something like a Pizza night or a new toy or game - like a trading stamp collection.