The number $97,640$  rounded off to the nearest thousands is

If the digit at the thousand’s place is 5 or greater than $\text{'}5\text{'},$  then  increase the thousand’s place digit  by 1 and replace the remaining( hundreds, tens and ones) places by ”0”.

In $97640\to$   thousand’s place digit  is $\text{'}7\text{'}$

So $97640$ is  rounded off to $98000$ .