Rounding is a method used to make numbers shorter and simpler by leaving off some of digits of smaller values. For the digit you are rounding, if it is less than 5, round down and equal to or greater than 5, round up.
Examples: 23,459 rounded to the thousands place is 23,000 and rounded to the hundreds place is 23,500. 0.089 rounded to the tenths place is 0.1.