Round 3184.5641 to the nearest hundred

Find the hundreds place. The digit in it is 1. Now look at the digit directly to the right of it. The digit is 8. If the digit immediately before the digit you want to round is greater than or equal to 5, you round up. 8 > 5, so round up.
The rounded value is 3200.
Hope that helped you.

3184.5641 - HUNDRED(s)
3184 rounded to the nearest hundreds = 3200. You look at the number before the place you're to round, depending on...
a) The number is 0-4, you round down.
b) The number is 5-9, you round up.
In this case, it's an 8, meaning you round up.

You're gonna need to post the table