Round each one to the nearest hundred.
[tex]\sf 457.03[/tex]
Look at the tens place, if the number is 5 or more you round up, if it is 4 or less you round down. The number in the tens place is 5, so we round up to 500:
[tex]\sf 500[/tex]
[tex]\sf 592.8[/tex]
Look at the tens place, if the number is 5 or more you round up, if it is 4 or less you round down. The number in the tens place is 9, so we round up to 600:
[tex]\sf 600[/tex]
Add the two rounded numbers:
[tex]\sf 500+600=\boxed{\sf 1100}[/tex]
