Do you mean If the rounded number is 30000 what is the greatest and least number that can rounded to it?
           if that the answer is                  rounded to nearest ten thousand
                      largest        34,999          30,000
                       least          25,000           30,000
34,999 rounded off to the nearest ten thousands is 40,000, or 35,000 to the nearest thousand. Please check the digits to the right. 4 will become 5.