Given : Airplane is 0.68 kilometers long
We know that :
⊕ 1 km = 1000 meters
⊕ 1 m = 1000 millimeters
⇒ 1 km = (1000 × 1000) millimeters
⇒ 0.68 km = (0.68 × 1000 × 1000) millimeters
⇒ 0.68 km = 680,000 millimeters
Answer: Airplane is 680,000 millimeters long
