By unit of length and distance and conversion ,we can say that
1 hm=100000 mm
78 hm=7800000 mm
6.3 centimeters equals 63 mm.
1000 mm equals one meter
1.5 cm equals 15 mm.
1 km equals 100,000 mm
15 mm
6,800 mm
63 mm
457.2 mm.
84 mm ;-)
It equals 35 mm.
1700 mm
2540 mm