title: CS50 - Compiling Issues
body: <p>I am currently taking the cs50 Harvard course via EDX and am working on the Cash/Greedy Algorithm problem from PSET1/Week1. I have it all written out and I keep getting this error;</p>
  <pre><code>~/pset1/ $ clang -o cash cash.c -lcs50
  /tmp/cash-4f9816.o: In function `main':
  cash.c:(.text+0x44): undefined reference to `round'
  clang-7: error: linker command failed with exit code 1 (use -v to see invocation)
  </code></pre>
  <p>Here is my code.</p>
  <pre><code>#include &lt;cs50.h&gt;
  #include &lt;stdio.h&gt;
  #include &lt;math.h&gt;
  int main(void)
      {
  
  float dollars;
  do
  {
      dollars = get_float(&quot;Change: &quot;);
  }
  while (dollars &lt;= 0);
  
  
  int cents = round(dollars * 100);
  int coins = 0;
  
  while (cents &gt;= 25)
  {
      coins ++;
      cents -= 25;
  }
  
  
  while (cents &gt;= 10)
  {
      coins ++;
      cents -= 10;
  }
  
  
  while (cents &gt;= 5)
  {
      coins ++;
      cents -= 5;
  }
  
  
  while (cents &gt;= 1)
  {
      coins ++;
      cents -= 1;
  }
  
  printf(&quot;You Will Receive %i Coin(s)\n)&quot;, coins);
   }
  </code></pre>
  <p>Can someone help me figure this out without breaking the Harvard honor code?</p>