Arabic Calculator

A calculator that has a peculiar attachment, usually Semtex in the form of C4, which is wired to the calculator in such a way that a value input into the calculator causes it to start a timer or directly cause the ignition of the explosive element, causing severe damages to property, and personnel.
e.g "My friend Mahmoud used his calculator in maths class and the school blew up"

Person 1: Could you please take out your calculators for this lesson?
Person 2: Alright (in the motion of taking out Arabic calculator)
Person 3: (Profuse screaming and inciting of panic)
Person 2: (Explodes)