Mathematics

Mathematics was the study of numbers.

Romulus and Remus Sylvest were mathematical geniuses. (TV: The Twin Dilemma) Peter Hutchings was a professor of mathematics at the University of Cambridge. (PROSE: Timewyrm: Revelation) Danny Pink taught mathematics at Coal Hill School. (TV: Into the Dalek)

Some of the companions of the Doctor studied or taught mathematics. Jackson Lake was a mathematics teacher. (TV: The Next Doctor) Alistair Gordon Lethbridge-Stewart taught mathematics at Brendon Public School. (TV: Mawdryn Undead) Adric was awarded a gold star badge for mathematical excellence. (TV: Full Circle) Zoe Heriot introduced herself to the Second Doctor and Jamie McCrimmon as "astrophysicist, pure mathematics major", to which her colleague, Dr Gemma Corwyn, added "with honours." (TV: The Wheel in Space)

In mathematics, i was an imaginary number that was the value of the square root of negative one. (AUDIO: Iterations of I)

Block transfer computation
An application of mathematics known as Block Transfer Computation could be used to create objects and alter spacetime. (TV: Logopolis)

Recreational mathematics
The Tenth Doctor mentioned Recreational Mathematics, which involved the study of happy prime numbers. He seemed surprised it wasn't a regularly studied course. (TV: 42)