We could undoubtedly answer this question if we knew what a 'stike' is.
It may help a little to consider that a 'mm' is one-tenth the size of a 'cm'.
And then again, it may not help at all.
A cm is bigger.
21mm is bigger. There are 10 mm in 1 cm, so 2 cm would be 20 mm. 21 mm is bigger than 20 mm.
cm is bigger (1 cm = 10 mm)
12 cm is bigger than 98 mm which equals 9.8 cm
45 mm is bigger.
10 cm = 100 mm which is bigger than 38.5 mm
5.1 cm would be bigger because 5.1 cm -> mm = 51 mm, which is greater than 50 mm.
1 cm = 10 mm 1 mm = 0.1 cm
6 cm = 60 mm; hence 63 mm is bigger than 60mm or 6 cm.
1 cm = 10 mm, so the cm is bigger.