title: Error was not declared in this scope
body: <p>I'm making this simple code where if I put two numbers and it shows the solution. This is the code:</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  
  int main()
  {
      printf("Enter two numbers:")
      ;scanf("&amp;d &amp;d", a, b)
      ;printf("=======================\n"); /*  */
      /*  */
      printf("The sum of %d and %d is %d.\n\n", 3, 4, 3 + 4)
      /*  */
      ;printf("The difference of %d and %d is %d. \n\n", 3, 4, 3-4)
      /*  */
      ;printf("The product of %d and %d is %d. \n\n", 3, 4, 3*4)
      /* sum of squares would be a*a + b*b */
      ;printf("The sum of the squares of %d and %d is %d. \n\n", 3, 4, 3*3 + 4*4)
      ;printf("**end**"); /* :-) */ 
      ;return (0);
  }
  </code></pre>
  
  <p>and I keep getting an error that says:</p>
  
  <pre><code>[Error] 'a' was not declared in this scope 
  and
  [Error] 'b' was not declared in this scope
  </code></pre>
  
  <p>What's wrong with it?</p>