Answer:
Ben interchanged the hundred thousands and million digits with each other.
Ben can fix his mistake by switching both digits.
Explanation:
We have been given that American car makers produce 5,650,000 cars each year. In a report, Ben wrote that Americans made 6,550,000 cars.
We can see that Ben interchanged the hundred thousands and million digits with each other.
Therefore, Ben can fix his mistake by switching both digits.