title: R Divide all rows of a dataframe column by a number
body: <p>I am trying to divide all rows of my dataframe column by a number (say 10). I thought it to be a trivial problem until I tried it. In the example below, I am trying to get the 'mm' column to result in values 8100, 3222.2 and 5433.3</p>
  
  <pre><code>test &lt;- data.frame(locations=c("81000","32222","54333"), value=c(87,54,43))
  test$mm &lt;- as.numeric(test$locations) / 10
  head(test)
       locations value  mm
     1     81000    87 0.3
     2     32222    54 0.1
     3     54333    43 0.2
  </code></pre>
  
  <p>What am I doing wrong? </p>