you would measure a wall in meters
Meters.
Meters
meters
centimeters
centimeters
Meters.
Meters
Neither. By centimeters
in centimeters
decameter
centimeters
meters
centimeters
Any of those units could be used. 'Kilometers' would result in the most convenient number.
centimeters
Divide the measurement in centimeters by 100,000. In other words, move the decimal point 5 places to the left. Example: 500,000 centimeters = 5 kilometers
Kilometers