Numbers can be rounded to the nearest ten, hundred, thousand etc. We also round decimals to the nearest tenth, hundredth, thousandth etc.
The first step is to look at the number to the right of the named place. If the digit is 5 or more, add 1 to the digit in the named place and replace the remaining digits with zeros.
If the digit is less than 5, leave the digit in the named place unchanged and replace the remaining digits with zeros.