Answer: 
1. 600,000
2. 8
3. 80
4. 130,000
Explanation:
1. If you know that 1 kilo meter is 1000 liters 
 And you know that there are 100 centiliters in one liter
 Then, do the math
2. When you know that there are 100 meters in a hectometer
 Then do the math
3. If you know that there are 100 decimeters in a dekameter
 Then do the math
4. If you know that there are 100,000 milligrams in a hectogram
 Then do the math