title: function to extract first 2 digits of 5 digits numbers within a dataframe in r
body: <p>How to select first 2 digits of a number? I just need the name of the function </p>
  
  <p>Example:   12455 turns into 12, 13655 into 13</p>
  
  <p>Basically it's the equivalent of substring for integers.</p>