Question

Round 8624 to the nearest thousand

Answer 1

You round to 9000

8 rounds up to 9 giving you 9000

Answer 2

To round to the nearst thousands, you check the digit after the one in the thousands position (this means you check the digit in the hundreds position), if this digit is equal to or greater that 5 then you will add 1 to the thousands and all other digits will be zeroes, otherwise, you won't add anything and only change other digits to zeroes.
applying this here, you will find that the number in the hundreds position is 6 which is greater than 5,
therefore 8624 to the nearest thousands is 8700