To the nearest 100, one hundred whole numbers will round - half of them up, half of them down.
To the nearest 100, the numbers 88,500 ± (100 ÷ 2) will round to 88,500; except that numbers exactly half way round up, so: 88,500 - 50 ≤ number < 88,500 + 50 will round to 88,500 to the nearest 100, ie 88450 ≤ number <88,550, thus the hundred whole numbers:
88 450, 88 451, 88 452, ..., 88 499, 88 500, 88 501, ..., 88 548, 88 549
All numbers can be rounded to the nearest ten.
There are infinitely many such numbers.
999 of them.
70
0
All numbers can be rounded to the nearest ten.
An infinite number.
88500
530
The numbers 250-259 can be rounded to 300. Also 301-349 can be rounded down to 300. This works if you are rounding by the nearest hundreds place.
1000
There are infinitely many such numbers.
999 of them.
70
70
33,500,000 to 34,499,999
340