So you got your new iPad, the IRS is auditing last year's tax return, and you ran out of fingers to add up all the receipts for lap dances you comped for your $100k a month client at the cow tongue pregnant stripper club. You tap the calculator app icon and get a pop up of a horse sodomizing some female porn star with a bunny costume on.
Whoops, the Apple developer got drunk and threw up on the keyboard before he could finish the code on the calculator app that was supposed to be included with the iPad. Guess Apple
thought that math was only for foreigners. And yes, you can get four-function calc apps on iTunes for the price of bootleg liquor that will leave you blind when you wake up on a spinning mattress.
But why go old school when you can go back to a time when you could chop the heads off of concubines if your dinner wasn't ready when you got back from putting arrows through samurai's throats? Like, say, all the way back to ancient China when they used to leave poopoo platter next to a dead corpse covered in clay in the living room?
The Digital Abacus app turns your iPad into the classic pre-school bead-and-rod addition/subtraction board that your son uses to throw as a frisbee at the LCD screen you got to buy for yourself on Father's Day.
Wash the cocaine out of your finger nail and use your booger finger to push the desired number of beads in each column up and down the rods. Assuming all the marijuana shotguns through your Darth Vader gas mask didn't completely erase your memory and you still remember how to "carry the one," adding and subtracting numbers is as obvious as throwing back black shrimp in the Gulf of Mexico.
The app includes an LCD-style digital readout you could see through even if the drunk chick from The 40 year old virgin threw up shellfish mixed with strawberry daiquiri on it.