Look at the digit after the thousandth one. If it is larger than or equal to 5, we round up. Otherwise, we round down.
So:
I know how to round off very decently but I have to ask this question.
I need to round off 242.48407 to the nearest thousandths.
I look at the number to the right of 4 and notice there is a zero there.
Would the answer be 242.484 or 242.485?
Thanks