10 mm = 1 cm so 400
400 cm its not that hard
40 cm = 400 mm 100 mm = 10 cm 100 cm = 1 metre
4, there are 10mm in 1cm
4000
4000mm
400 centimeters=4000 millimeters
By unit of length and distance and conversion ,we can say that 1 cm=10 mm 400 cm=4000 mm
there are 10 mm in 1 cm so; 400 cm ( 10 mm / 1 cm ) = 4000 mm
40 centimetres is equivalent to 400 millimetres
400 mm = 40 cm
1 cm = 10 mm so 40 cm = 40*10 = 400 mm. Simple!