01-07 05:32:27.258: WARN/dalvikvm(227): threadid=3: thread exiting with uncaught exception (group=0x4001b188)

01-07 05:32:27.268: ERROR/AndroidRuntime(227): Uncaught handler: thread main exiting due to uncaught exception

01-07 05:32:27.308: ERROR/AndroidRuntime(227): java.lang.NullPointerException

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at com.xrath.training.android.calculator.ButtonActions.processNumber(ButtonActions.java:18)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at com.xrath.training.android.calculator.ButtonGroup$1.onClick(ButtonGroup.java:40)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.view.View.performClick(View.java:2364)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.view.View.onTouchEvent(View.java:4179)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.widget.TextView.onTouchEvent(TextView.java:6532)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.view.View.dispatchTouchEvent(View.java:3709)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1659)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.app.Activity.dispatchTouchEvent(Activity.java:2061)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1643)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.view.ViewRoot.handleMessage(ViewRoot.java:1690)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.os.Handler.dispatchMessage(Handler.java:99)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.os.Looper.loop(Looper.java:123)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at android.app.ActivityThread.main(ActivityThread.java:4310)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at java.lang.reflect.Method.invokeNative(Native Method)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at java.lang.reflect.Method.invoke(Method.java:521)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)

01-07 05:32:27.308: ERROR/AndroidRuntime(227): at dalvik.system.NativeStart.main(Native Method)

지금 rath world라는 곳에있는 계산기를 만들어볼려고하는데요
일단 에뮬 실행되고하는데요
/, *, -, +, = 는 눌러도 아무런 이상이 없는데
숫자버튼이랑 dot버튼을 누르면 the application(process com.xrath....) has stopped unexpectedly Please try again.
이렇게 오류가 나는데 왜 그렇지 찾을수가 없어서 문의드립니다....
안드로이드를 이번에 처음 접해서 아는게 없네요....
답변주시면 감사하겠습니다.
http://xrath.com/2009/11/android-%ec%8a%a4%ed%84%b0%eb%94%94-%ea%b3%84%ec%82%b0%ea%b8%b0-%eb%a7%8c%eb%93%a4%ea%b8%b0/