title: Rounding necessary with BigDecimal numbers
body: <p>I want to set scale of two BigDecimal numbers <code>a</code> and <code>b</code> . as in this example :</p>
  
  <pre><code>BigDecimal a = new BigDecimal("2.6E-1095");
          BigDecimal b = new BigDecimal("2.7E-1105");
          int i = 112, j=1;
  
          BigDecimal aa = a.setScale(i+j);
          BigDecimal bb = b.setScale(i+j);
  </code></pre>
  
  <p>and when i run i have this exception:</p>
  
  <pre><code>java.lang.ArithmeticException: Rounding necessary
      at java.math.BigDecimal.divideAndRound(BigDecimal.java:1439)
      at java.math.BigDecimal.setScale(BigDecimal.java:2394)
      at java.math.BigDecimal.setScale(BigDecimal.java:2437)
  </code></pre>
  
  <p>Why rounding is necessary ?  if i don't want to make around, what is solution please ?</p>
  
  <p>Thanks</p>