Answer:
500
When rounding to the nearest hundred, like we did with 545 we use these rules
first you would have to round the number up to the nearest hundred if the last two digits in the number are 50 or above.
then you would have to round the number down to the nearest hundred if the last two digits in the number are 49 or below.
lastly you would have to see if the last two digits are 00, then we do not have to do any rounding, because it is already to the hundred.