It then is 9000 when rounded to the nearest thousand
8536 to the nearest 1000 is 9000. When rounding to the nearest 1000, you look at the hundreds place. Since the digit in the hundreds place is 5 or greater, you round up to the next thousand, which is 9000.
Well, honey, 8536 rounded to the nearest 100 is 8500. Just chop off those last two digits like they're split ends and call it a day.
1000
1000
176 rounded to the nearest 1000 is 0
1000
0
214357000
128000
921 rounded to the nearest ten thousand is 0. Rounded to the nearest thousand is 1000.
1000
1000