Can someone help me with a tutorial I found?

I was hoping to make an Android calculator and I came across this article: http://www.codeproject.com/Articles/104931/Introduction-to-Android-development-TouchCalculato?msg=4294189#xx4294189xx

Anyway, I followed the instructions and put all the code into the right files using Eclipse with the ADT plugin. Everything seems to be fine except for the main.java file which seems to have errors every other line. Could someone please explain how to do this tutorial properly?