The Cardboard Half-Pipe

I propped up a curved cardboard coaster against a thick notebook to see if I could build the ultimate mini ramp! A shiny blue marble was my test rider. The first launch shot wildly sideways and bounced straight into a roll of masking tape, but I quickly wedged a pink eraser under the base for extra lift. On the second try, whoosh! It sailed down the curve and dropped right into an empty tin can with a loud, ringing clatter. Nailed it on try two!