What is the largest number that will round up or down to 500?
The largest number that will round up or down to 500 is 499.5. When rounding to the nearest whole number, 499.5 would round up to 500. Similarly, when rounding to the nearest ten, hundred, or thousand, 499.5 would also round to 500. Any number greater than 499.5 would round up to a number greater than 500.