Arrange the lengths , , , and in descending order.
Converting the measurements to the same unit can help us arrange the lengths.
There are centimetres in 1 kilometre, so we multiply the number of kilometres by to convert the second length to centimetres.
There are 100 centimetres in 1 metre, so we multiply the number of metres by 100 to convert the third length to centimetres.
There are 10 centimetres in 1 decimetre, so we multiply the number of decimetres by 10 to convert the fourth length to centimetres.
centimetres > centimetres > centimetres > centimetres, so the lengths arranged in descending order are dm, cm, km, m.