It is replacing the number by the whole number such that the difference between the number and that whole number is the smallest that it can be.
650
693500
750000 to 849999
It is: 500
The smallest whole number that can be rounded to 500 is 450.
It is replacing the number by the whole number such that the difference between the number and that whole number is the smallest that it can be.
The answer will depend on the degree of rounding: to the nearest ten, hundred, thousand?
650
693500
750000 to 849999
It is: 500
800
The smallest number that is 600 when rounded to the nearest hundred is 550. The largest number that is 600 when rounded to the nearest hundred is 649.
150
6500
70