It depends on whether you are rounding to the nearest ten of hundred (or even twenty).
945,000 / 3 = 315,000 so that is the middle number then 1 either side. 314,999 + 315,000 + 315,001 = 945,000
5499999
14,000
1549
Nine of them.
99 of them.
The numbers from 75 to 84 are rounded off to 80 to the nearest ten
3 and these are 600,650,and 700
Since numbers equal to or greater than 5 are rounded up, and numbers equal to or less than 4 are rounded down, the largest 4-digit number that can be rounded off to 3000 would be 3004.
999 of them.
Ten integers can be rounded off to 280. An infinite number of numbers can be rounded off to 280.
Infinitely many.
16 is rounded to 20 if rounded to the ten's digit.
Infinitely many.
35 to 44
245 to 254