100 (number)

100 was a number.

A chalkboard at Coal Hill School in November 1963 referenced "100 Cents". (TV: "An Unearthly Child")

Sunday was 100 light-years from Earth, (PROSE: Wetworld) as was Beta Caprisis. (PROSE: Sanctuary)The Master once bribed an architect to make the Spikes of Doom, having travelled back 100 years before he was to meet with the Ninth Doctor and his companion Emma at Castle Tersurus. The Doctor travelled back to bribe the architect at an earlier point, causing them to instead be subjected to the Sofa of Reasonable Comfort. (TV: The Curse of Fatal Death)

At Rose Tyler's request, the Ninth Doctor took the TARDIS a hundred years through the Time Vortex from 2005 to 2105. However, the Doctor claimed that it was "a bit boring" and so they went even further into the future before stepping out of the TARDIS. (TV: The End of the World)

In maths, 258 minus 158 was 100. Rose Tyler answered this correctly in The Weakest Link. (TV: Bad Wolf)

As Ood Sigma revealed to the Tenth Doctor when he returned to the Ood Sphere, one hundred years had passed following his involvement in the Revolution of the Ood. (TV: The End of Time) The ISO used by Giles when he talked to a camera about PROBE and leads in a case regarding an upcoming perihelion was 100. (WC: Out of the Shadows)

References in invalid sources
The Doctor's Five Hundred Year Diary referenced "[ sums] of human knowledge" of 25%, 50%, 75%, and 100%. When it displayed 100, the text was red. (NOTVALID: Tom Baker stars in John Lloyd's lost Doctor Who adventure, The Doomsday Contract)