10 (number)
From Tardis Wiki, the free Doctor Who reference
10 was a number.
According to Jo Grant, 98 plus 10 was equal to 108. (TV: The Claws of Axos)
When discussing his regeneration cycle, the Eleventh Doctor confirmed that he had used up his regeneration, as his previous self, who he called "Number Ten", used two regenerations. [source needed]
