Facebook SDK instruction not making sense about app id

I have taken a picture of the Facebook instruction below. What is wrong with it? My app keeps crashing with exception concerning ApplicationId should not be null. But I have added my app id as <meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/facebook_app_id"/> in the manifest; that is after adding it as a string in the strings.xml resource as <string name="facebook_app_id">0000000000</string>

So I figure the instructions is wrong because it does not say which uses-permission to add and it says to call the string resource key com.facebook.sdk.ApplicationId with value Facebook_app_id. Here is the link http://ift.tt/1ydPkvr