A worker in a factory earns $10 an hour. The worker works 10 hours a day for 10 days straight before a vacation. How much money did the worker earn before going on vacation??
The worker earns $10 per hour and works 10 hours a day for 10 days, so the worker earns $10 * 10 = $<<10*10=100>>100 per day.
Therefore, the worker earned a total of $100 per day * 10 days = $<<100*10=1000>>1000 before going on vacation. Answer: \boxed{1000}.