What is 121,580 Rounded to the nearest thousand?

122000 is the answer.

To round, you must see if the number coming before the place you're rounding to is greater than or equal to 5. In this case, it's the hundreds place, and it is 5, so you would round up. (If it was less, you'd round down to 121,00.) To round up, we raise the thousands place by 1. Therefore, the answer is 122,000.