Because we muliply the three sides of a cube of one meter length x 3. =1000x1000x1000=1,000,000
1 km = 1000 m 1 cu.km = 1000x1000x1000 cu.m Hence the conversion is multiply cu.km by 109.
You multiply by 1,000,000,000. This is gotten in the following way. There are 1000mm in a metre. As you cube the units, you also cube the difference. i.e. 1000x1000x1000, which gives 1 billion or 1,000,000,000.
Because we muliply the three sides of a cube of one meter length x 3. =1000x1000x1000=1,000,000
1 km = 1000 m 1 cu.km = 1000x1000x1000 cu.m Hence the conversion is multiply cu.km by 109.
You multiply by 1,000,000,000. This is gotten in the following way. There are 1000mm in a metre. As you cube the units, you also cube the difference. i.e. 1000x1000x1000, which gives 1 billion or 1,000,000,000.
A millimeter is 1/1000th of a meter. 1000 millimeters in a meter. So; 1000x1000x1000 (length x width x height) cubic millimeters in a cubic meter = 1,000,000,000 (billion). 1000 liters to a cubic meter. A liter is 1/1000th of a cubic meter. Therefore; 1,000,000,000 / 1000 = 1,000,000 millimeters in a liter.