I free feed all my kids but if you're still potty training, you might want to feed on a schedule. Whatever your chi eats in about 15 mins should be the amount that you feed them. At 10 weeks, I would say 3 times a day. If you're trying to potty train, most puppies will have to poop within an hour of eating. For some dogs it will be 5 mins and some dogs it will be 1 hour. So if you feed on a schedule and then know they will have to poop soon, you can get them outside (or to paper, whatever) to reinforce good potty habits.
Since all my kids are potty trained and since little dogs generally like several small *meals* throughout the day, we free feed.