title: from keyword in wrong place
body: <p>Display realtor staff number, name, annual salary as Annual Salary, monthly salary as Monthly Salary, and age as Age. Round monthly salary to 2 decimal places. Round age to years. Sort output by staff age descending.  If there is no birthdate on the record, then list the age as "Unknown".
  This is the code I have to answer the question. </p>
  
  <pre><code>select st_staffno, st_name, st_salary "Annual Salary",(st_salary/12) as "Monthly Salary"   
      decode (st_birthdate, null, 'unknown'), 
      round sysdate ((st.birthdate)/365.25,0) as "Age"
  from staff
  order by "Age" desc;
  </code></pre>
  
  <p>It is returning a From keyword not found where expected error.</p>