Help me to fix error getting at runtime
<p>I'm new to android dev and i developed a sample proj named Math in that i created two windows one is entering the values and second one is to display the result. But the problem is when ever i entered the values and click on GO button it giving me some error. You can download my proj from link below:</p>

<p><a href="https://skydrive.live.com/?cid=12A251B09B8A1A55&amp;id=12A251B09B8A1A55!112&amp;sc=documents#!/?cid=12a251b09b8a1a55&amp;sc=documents&amp;id=12A251B09B8A1A55!114" rel="nofollow">https://skydrive.live.com/?cid=12A251B09B8A1A55&amp;id=12A251B09B8A1A55!112&amp;sc=documents#!/?cid=12a251b09b8a1a55&amp;sc=documents&amp;id=12A251B09B8A1A55!114</a></p>

<p>Thanks,</p>
