In order to figure out the question you have to first get familiar with the places.
hundred thousands ten thousands thousands hundreds tens ones
3 8 7 4 2 2
Now that you know what all the places are you can round.
Since it is asking for the hundred thousands place, you can look and see that there is a 3 there. In order for that number to round up to 4, the number in the ten thousands place would have to be 5 or greater. Since it is an 8, it can be rounded up. Once you round up, you have to change every number behind the hundred thousands place to 0.
It should look like this:
4 0 0 0 0 0
I hope this helped!