Estimating 
    is an important part of mathematics and a very handy tool for everyday life. 
    Get in the habit of estimating amounts of money, lengths of time, distances, 
    and many other physical quantities. 
  Rounding 
    off 
    is a kind of estimating. 
  To 
    round off decimals: 
    
  
    - Find the 
      place value you want (the "rounding digit") and look at the digit 
      just to the right of it.
 
    - If that digit 
      is less than 5, do not change the rounding digit but drop all digits to 
      the right of it.
 
    - If that digit 
      is greater than or equal to five, add one to the rounding digit and drop 
      all digits to the right of it.
 
  
  To round 
    off whole numbers:
  
    - Find the 
      place value you want (the "rounding digit") and look to the digit 
      just to the right of it.
 
    - If that digit 
      is less than 5, do not change the "rounding digit" but change 
      all digits to the right of the "rounding digit" to zero.
 
    - If that digit 
      is greater than or equal to 5, add one to the rounding digit and change 
      all digits to the right of the rounding digit to zero. 
 
  
  Move 
    your mouse cursor over each digit in the number below to round the number 
    to that place.