4 (number)
4 was a number.
According to Jo Grant, three sevens times four were equal to 84. Also according to her, 12 divided by 4 was 3. (TV: The Claws of Axos)
Some species, like the Empathivores, (COMIC: The Whispering Gallery) the Moxolon Swamp Vipers, (TV: The Vault of Secrets) the Tractites (PROSE: Genocide) and the Tetraps (TV: Time and the Rani) had four eyes.
Vulpana had four moons. (AUDIO: The Moons of Vulpana)
The Fifth Doctor told the First Doctor that he was on his fourth regeneration. (TV: The Five Doctors)
The Fifth Doctor was told by Alistair Gordon Lethbridge-Stewart that he had worked with eight other incarnations of the Doctor by 1999, including four of his future incarnations. (PROSE: The King of Terror)
Graffiti on the outer walls of Deffry Vale High School by 2007 read "Paul 4 Claire". (TV: School Reunion)
To his recollection, Elton Pope saw the Tenth Doctor on the night of his mother's death when he was "three or four" years old. (TV: Love & Monsters)
Before the Genesis Ark opened, the Doctor believed that the Cult of Skaro were the last four Daleks in existence. (TV: Doomsday)
The countdown towards the Ninth Doctor's eviction on Big Brother counted from 6 to 0, going through 5, 4, 3, 2, and 1. (TV: Bad Wolf)
In an emergency transmission sent by the TARDIS, the Thirteenth Doctor listed five things that she did in any worrying situation. The fourth was listening to science and doctors. (WC: Message from the Doctor)
In 1999, the Ninth Doctor had a conversation with "Eddie Duggan" on a flight of stone steps in a square in Prague at 4AM. (PROSE: Have You Seen This Man?)
