You have the wrong understanding of millimeters. A Newton.meter is a unit of work, it is called the Joule in the SI system. A millimeter is a distance, equal to 1/1000 of a meter.
newtonmeter
newtonmeter (Nm) or Joule (J)
4.4 millimeters = 4.4 millimeters.
some scales, a newtonmeter maybe...
20 millimeters
Exactly three millimeters.
2.135 meters to millimeters = 2135 millimeters
75.3 centimeters is 753 millimeters.
7500 millimeters.
400!
90 Millimeters 90 Millimeters
There are 10 millimeters per centimeter.