You can learn to convert km units into cm by using the SI base unit for measuring length which is the meter. You need to know the basics of cm and km. cm stands for Centimeter while km means Kilometer. In the SI base unit/Metric System, each Centimeter is equal to 100 meters while each Kilometer is equal to 1000 meters.
You can learn to convert km units to cm in your head by simply dividing the given kilometer by the number 10 and you will get the correct cm unit. For example, you are given 2 kilometers and asked to find its cm. The cm will be gotten by dividing this way: 2km=2000 meters divided by 2cm which is 200 meters. The answer will be 20cm.