Another great idea from Productive Parenting, this is an activity I just knew Erik would enjoy. He loves playing with balls, so anything that incorporates that love is a hit. It's super easy. All you need is a ball (or two, or three...) and something with which to build a ramp. We used a flattened cardboard box leaned against a chair, but you could use a cookie sheet or a stack of books or anything else you can find. Productive Parenting suggests setting up an empty milk jug at the bottom to try to bowl over, but I didn't want to wait until we'd finished one off. You could just skip this part or do like we did and put a basket at the bottom to catch the ball.