calculator errors

11-13 22:11:43.455: E/AndroidRuntime(906): FATAL EXCEPTION: main
11-13 22:11:43.455: E/AndroidRuntime(906): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.aaaaa/com.example.aaaaa.MainActivity}: android.view.InflateException: Binary XML file line #79: Error inflating class <unknown>
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.app.ActivityThread.access$600(ActivityThread.java:141)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.os.Handler.dispatchMessage(Handler.java:99)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.os.Looper.loop(Looper.java:137)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.app.ActivityThread.main(ActivityThread.java:5041)
11-13 22:11:43.455: E/AndroidRuntime(906):  at java.lang.reflect.Method.invokeNative(Native Method)
11-13 22:11:43.455: E/AndroidRuntime(906):  at java.lang.reflect.Method.invoke(Method.java:511)
11-13 22:11:43.455: E/AndroidRuntime(906):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
11-13 22:11:43.455: E/AndroidRuntime(906):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
11-13 22:11:43.455: E/AndroidRuntime(906):  at dalvik.system.NativeStart.main(Native Method)
11-13 22:11:43.455: E/AndroidRuntime(906): Caused by: android.view.InflateException: Binary XML file line #79: Error inflating class <unknown>
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.view.LayoutInflater.createView(LayoutInflater.java:613)
11-13 22:11:43.455: E/AndroidRuntime(906):  at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:56)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.view.LayoutInflater.onCreateView(LayoutInflater.java:660)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:685)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
11-13 22:11:43.455: E/AndroidRuntime(906):  at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:270)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.app.Activity.setContentView(Activity.java:1881)
11-13 22:11:43.455: E/AndroidRuntime(906):  at com.example.aaaaa.MainActivity.onCreate(MainActivity.java:52)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.app.Activity.performCreate(Activity.java:5104)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
11-13 22:11:43.455: E/AndroidRuntime(906):  ... 11 more
11-13 22:11:43.455: E/AndroidRuntime(906): Caused by: java.lang.reflect.InvocationTargetException
11-13 22:11:43.455: E/AndroidRuntime(906):  at java.lang.reflect.Constructor.constructNative(Native Method)
11-13 22:11:43.455: E/AndroidRuntime(906):  at java.lang.reflect.Constructor.newInstance(Constructor.java:417)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.view.LayoutInflater.createView(LayoutInflater.java:587)
11-13 22:11:43.455: E/AndroidRuntime(906):  ... 25 more
11-13 22:11:43.455: E/AndroidRuntime(906): Caused by: android.content.res.Resources$NotFoundException: Resource is not a ColorStateList (color or path): TypedValue{t=0x1/d=0x7f070001 a=-1 r=0x7f070001}
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.content.res.Resources.loadColorStateList(Resources.java:2074)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.content.res.TypedArray.getColorStateList(TypedArray.java:342)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.widget.TextView.<init>(TextView.java:904)
11-13 22:11:43.455: E/AndroidRuntime(906):  at android.widget.TextView.<init>(TextView.java:578)
11-13 22:11:43.455: E/AndroidRuntime(906):  ... 28 more