It remains the same because when you round it the number next to it is not 5 or higher so it stays the same . Remember when your rounding the number next to it has to be 5 or higher or it will not change if it not 5 or higher .
❖ The 3 remains the same when 9,321 is rounded because if you look to the right of the number in the hundreds place, you see 2. 5 and above, give it a shove (round up). 4 and below, leave it alone (round down). Since 2 is below 5, we leave it alone. So 9,321 is rounded to 9,300.