The greatest whole number would be: 456,949
If you round 456,949 to the nearest hundreds, you would get 456,900.
Here's how:
1. The number '9' is located in the hundreds place
2. Since the number '4' is located in the tens place, it's telling the number '9' to stay the same
Stay the Same: ,2,3,4
Goes Up; 5,6,7,8, etc.
456,949 ⇒ 456,900