5 and above, give it a shove. 4 and below, let it go.
Meaning, if the number is greater than 5, round up. If it less, let it as is.
Now are you rounding to the nearest 100 or 100,000? Your question has it as 100.000 which would be 100. But you have three 0's after the period. So, I'm not sure. I'll just do both to be safe.
5,382,619
Rounding to the nearest 100,000
Using the number 5,382,619 you would be rounding using the 3. To round, you look at the number directly to the right which would be an 8.
Since it is part of "5 and above" you are going to give it a shove, or increase the 8 by 1. And all the numbers following turn into zero's.
5,390,000
If you are rounding to the nearest 100, the number you would be using is 6. Look directly to the right of the 6. Is the number greater or less that 5? Less than. So, let the 1 be and turn the rest of the numbers into zero's.
5,382,610