8,589 rounded to nearest thousand

If this were a physics lab, you could get away by rounding to 8000

However since your in middle school, following the rules of rounding, the hundreds place is 5 so we round up to ...

"9000"

8 is the thousands place. Look at the digit of the right of it. It is 5.

Is it greater or equal to 5? Yes it is. Round up.

Answer: 9,000