Here's how to convert decimeters (dm) to hectometers (hm):

* Understanding the Units:

* 1 hectometer (hm) = 100 meters (m)

* 1 meter (m) = 10 decimeters (dm)

* Conversion Steps:

1. Convert decimeters to meters: 1550 dm / 10 dm/m = 155 m

2. Convert meters to hectometers: 155 m / 100 m/hm = 1.55 hm

Therefore, 1550 dm is equal to 1.55 hm.