10
500 decimeters = 50 meters
There are 10 metres in one decametre. Therefore, 0.1 decametres is equal to 0.1 x 10 = 1 metre.
There are 10 metres in one decametre. Therefore, 20.8 decametres is equal to 20.8 x 10 = 208 metres.
100000
There are 10 meters in a decameter. The prefix deca- signifies a factor of ten. Not to be confused with the decimeter, which is a tenth of a meter. Both are very rarely used. Much more common are...