This math topic focuses on calculating distances based on given speeds and times, with an emphasis on converting between different units of measurement. The problems involve a variety of scenarios featuring different moving objects such as bacteria, bugs, and cars. Each question requires converting the calculated distances into units like millimeters, centimeters, and meters from the original unit in which speed or time is given. This set of problems helps strengthen skills in unit conversion and application of the speed-distance-time relationship in contexts that involve advanced changes in distance units.