Not a very sensible conversion. a gegametre, 1 Gm, is one billion metres; a millimetre , 1mm,is one one thousandth of a metre.
1 Gm = 1 000 000 000 m; 1 mm = 0.001 m.
1 mm = 1 x 10-12 Gm
200 mm = 200 x 10-12 Gm, 0.000 000 000 200 Gm.
That answer is correct.
0.001 gigameters how did you work the problem to get the answer?
The answer you calculated is clearly WRONG! 200mm = 0.2 metres or 2*10-1 metres = 2*10-4 kilometres = 2*10-7 megametres = 2*10-10 gigametres.
200 kilometers is 200,000,000 millimeters.
200 millimeters are 20 centimeters or 0.2 meters.
Exactly 200.
200 meters is 200,000 millimeters.
.0002 millimeters
200 millimeters = 0.66 feet.
200 centimeters = 2,000 millimeters
200 mm = 0.656 feet
200 millimeters is 20 centimeters.