Here's why:

* Decigram (dg): A decigram is one-tenth of a gram (1 dg = 0.1 g).

* Kilogram (kg): A kilogram is one thousand grams (1 kg = 1000 g).

Therefore:

* 1000 dg = 1000 * 0.1 g = 100 g

* 100 g = 0.1 kg = 1/10 kg

* 1000 dg = 1 kg