To determine the conversion from mm to cm to m to dm to km:
[tex]\begin{gathered} \operatorname{mm}\text{ => Millimtere} \\ \operatorname{cm}=>\text{centimetre} \\ m\Rightarrow\text{ metre} \\ dm\Rightarrow\text{ decimetre} \\ \operatorname{km}-\text{kilometre} \end{gathered}[/tex]Conversion from mm to cm =
[tex]10\text{ mm }\Rightarrow\text{ 1 cm}[/tex]Conversion from cm to m
[tex]100\operatorname{cm}\Rightarrow\text{ 1m}[/tex]Conversion from m to dm
[tex]1m\Rightarrow\text{ 10dm}[/tex]Conversion from dm to km
[tex]10000dm\Rightarrow\text{ }1\text{ km}[/tex]Hence the correct conversion are
10 mm = 1 cm
100 mm = 1 dm
1000 mm = 1 mm
1000000 mm = 1 km