Story of Ganesha's broken tusk

Shri Ganesh had two tusks, but he had a great fight with Parshuram, when Ganesh laid claims to immortality.
 
 There are only seven who are immortal :-
 1) Shri Hanumanji
 2) Vibhishan
 3) Kripacharya
 4) Shri Parshuram
 5) Ashwathama
 6) Bali and
 7) Ved Vyas (Markandey Rishi also joined their ranks later)
 
 These great men do not die and even when the world dissolves and a new world takes birth they will be here.
 
 They are not born again and again. They live on the mighty Himalayas and it is said that some great souls do come across them.
 
 Anyway, Shri Ganesh declared that he was eligible for such a position, but Shri Parshuram was not satisfied and wanted to test him. Parshuram loses his temper at the drop of a hat (as the saying goes), so he declared he would fight with Shri Ganesh; and if Shri Ganesh won, only then he would be immortal.
 
 There ensued a terrible battle. Shri Parshuram became very ferocious in the heat of the moment and in the process he dealt a deadly blow, which Shri Ganesh took on his left tusk and as a result, it broke in the heat of the battle.
 
 From that moment on, Shri Ganesh is called as Ekdant (The ONE with One Tusk)
 
 Shri Ganesh was chosen by Naradji to write down the Mahabharata for posterity, while Ved Vyasji related the tale of his grandsons to him.
 
 He chose his broken tusk to write.
 
 He told Vyasji that he would only write if he gave the dictation continuously and did not stop or hesitate and waste time.
 
 His mother Bhagwati (Parvati) asked Shri Ganesh to also use his buddhi while writing also and explain certain points so that the generations to come would understand the great epic as it was meant to be understood.
 
 SO IS THE REASON WHY Saraswati - The Goddess of Learning, is prayed to after Shri Ganesh. ...