Todd Bucciarelli of HInsdale shows the Tiger Cubs from Pack 10 one of the entries in the pinewood derbyheld Saturday. | Steve Johnston~for Sun-Times Media

Bear Scout Max Aschinberg of Hinsdale watches the Tiger Cubs races. At least 40 first- through fifth-graders raced Saturday in Pack 10's pinewood derby. | Steve Johnston~for Sun-Times Media

Gregory and George Theotikos of Hinsdale check the weight of their car for Cub Scout Pack 10's pinewood derby The cars cannot weigh more than 5 ounces.. | Steve Johnston~for Sun-Times Media

Mickey Moran and Robert Rocque input information before the start of Cub Scout Pack 10's pinewood derby Saturday. Sensors in the track record the start and finish time of each car to one-thousandth of a second. | Steve Johnston~for Sun-Times Media

Tiger Cubs watch as their cars race towards the finish line during Cub Scout Pack 10's pinewood derby. Each car races on all three lanes of the track, and its time is the average of the three races. | Steve Johnston~for Sun-Times Media