title: Working with Math class without instantiating it
body: <p>I am new to  programming and was studying "Head First Java",  I just saw  a problem where there was used <code>Math</code> class like this</p>
  
  <pre><code>int x= Math.round(float value);
  </code></pre>
  
  <p>and it was mentioned we don't need  to instantiate Math class because its constructor is set <code>private</code>. What does that mean? Until now  I read we need to instantiate that class and reference variable to play around with methods and instance variables of the class how does Math class work like this?  </p>