There are 10 mm to a cm so just times the number by ten, so 420mm = 4.2cm :)
1000 mm equals one meter
6.3 centimeters equals 63 mm.
1.5 cm equals 15 mm.
1 km equals 100,000 mm
15 mm
457.2 mm.
63 mm
84 mm ;-)
6,800 mm
It equals 35 mm.
Yes because there is 10 mm in 1 cm so 42 x 10 is 420
419 mm