mathemacations Share definition Flag Noun & Garethism. An amalgamation of maths and calculation first used by Gareth in the year 2004. We need to know the budget for the movie, have you done the mathemacations? mathemacations by GazelleH August 27, 2007 0 0 Get merch Get the mathemacations mug. Buy Now — $32.95 See more merch