To round a number to the nearest thousand, the digit in hundreds place is considered. if it is greater than or equal to 5 we round it up and if is less than 5 we round it down.
In 24,500 the hundreds place is 5 and the thousands place is 4.
Hence, increase the digit at thousands place by 1 and replace each one of the digits in hundreds, tens and ones place by 0
∴24,500 is rounded off to nearest thousands as 25,000.