To round them, you need to look at the number and understand what the place formats are. If a number is in the hundred thousand range, it would be 100,000, which means that the number 808,879 as a whole is a hundred thousand, making it 800,000 rounded to the nearest. It is 800,000 due to the thousands digits, (8,879) being small enough to not make it into 900,000. For the ten thousands spot, that would be the number as shown above, (8,879) making it rounded to 10,000. So that would mean if you are asking for both rounded at the same time, it would be 810,000. :)
