Bathroom math Share definition Flag During a toilet sesh, needing to go number one and number two at the same go, totaling three. Rudigger: Yo buddy, why were you in the stall so long? Jim: Got tied up with some bathroom math. Bathroom math by Just Dewar April 7, 2009 0 0 Get merch Get the Bathroom math mug. Buy Now — $32.95 See more merch