title: How to go about multiple Buttons and OnClickListeners
body: <p>I have in 16 <code>Button</code>s (numbers, plus, minus etc) in my layout XML file.</p>
  
  <p>I'm wondering how to check which button was pressed.</p>
  
  <p>My idea is, that I will for each button use <code>onClick()</code> method but this method is a bit impractically, because I will have 16 of these <code>onClick()</code> methods one for each Button.</p>
  
  <p>Is there a more elegant way?</p>