It depends on the degree to which the numbers are being rounded. 300 to the nearest 200, for example.
The least number that can be rounded to 400 (to the nearest 400) is 200.
673
673
The smallest number that can be rounded off to 400 is 350, as any number from 350 to 399.99 will round to 400. Conversely, the greatest number that can be rounded off to 400 is 449.99, since numbers from 400 to 449.99 will also round to 400.
To the nearest hundred, 400
We could have used that missing number. In general, the least whole number that will round to the nearest hundred is x50 of the previous one. 650 is the least whole number that will round to 700
the least number that round to 800000 is 750000 and the greatest number that round to 800000 is 849999.
round number of 2000000 to least and greatest number
349
85
350
400