500km + 200hm= ……….dam

500 km = 500 × 100 = 50.000 dam
200 hm = 200 × 10 = 2.000 dam
————————————————————— +
52.000 dam

500km =50000dam
200hm =2000 dam
Jadi 50000+2000 =52000.
Semoga benar…