How fast can you run? How fast are you growing? How fast do you read? There are many things in the world around you that are moving fast! But how do you measure them? The ideas in this book will help you perform exciting and fun experiments. Some will even give you ideas for your science fair. Using simple materials, you can do everything a scientist does: conduct experiments, keep records, and draw conclusions from what you have learned. You will then be ready to discover the fast world around you!