Answer:
490
Explanation:
To round a number to the nearest ten, you look at the digit in the tens place, which is the 9 in 493. If this digit is 5 or greater, you round up; if it's less than 5, you round down. In this case, 9 is greater than 5, so when you round 493 to the nearest ten, it becomes 490 because you round up to the next multiple of ten.