Three children were racing toy cars. They held them at the top of a ramp. When one said, “Go,” they all let go. The cars rolled down the ramp and across the finish line. The children timed their cars. The red car finished in four seconds, the white car finished in two seconds, and the blue car finished in six seconds. Question: Which car rolled the fastest? Explain how you know. Which car rolled the slowest? Explain how you know. If a fourth car was added to the race and came in second, how would you describe its speed?