When rounding to the nearest hundred, half will round down and half will round up, ie 100 ÷ 2 = 50 will round each way.
→ any number greater than or equal to 900 and less than 900 + 50 = 950 will round down to 900.
ie any number n such than 900 ≤ n < 950 will round down to 900 to the nearest 100.
Which means your [whole] number could be any of 900, 901, 902, ..., 949.
7550 is the smallest number than rounds to 7600 when rounded to the nearest hundred.
0
15,700,000 is already rounded to the nearest hundred thousands.
499
800
7200
8600
3200
7550 is the smallest number than rounds to 7600 when rounded to the nearest hundred.
200
The number 693 rounded to the nearest hundred is 700
199
150
450
0
15,700,000 is already rounded to the nearest hundred thousands.
499