They need to be rearranged to mean any thing in today's modern conversion:
M = 1000, D = 500 and C =100
MDC = 1600
MCD = 1400
25 dcm is 2,500 mm
445.65
1 kilometer=10,000 decimeters
2 kg are in 2000 grams. Use the device KHD b dcm.
A meter equals 1/10 0f a decimetre. So, 7 dcm equals 0.7 meters.