Getting your kid involved in the kitchen is always a good idea. Giving him a sharp knife is not. You want to teach him how to chop stuff (start him early on those knife skills!), but you certainly don't want to give him your dangerous eight-inch chef's knife. And none of his kid knives will cut it. (Get it?)
Consider picking up this Opinel Le Petit Chef's Knife, which is on sale for the next few hours.
Made by a classic French knife company, the four-inch knife is high-quality and perfect for kids who are learning the basics. The knife is made specifically for smaller hands, with a special ring to help position little fingers and keep hands from slipping onto the blade. It even comes with a plastic finger guard for extra protection (of course, adult supervision is still recommended).
Hurry, though, because this knife is on sale as an Amazon Lightning Deal and they're sure to go fast.