calcumaniac 

NOUN: Someone who is addicted or obsessed with using or becoming more aware of the operations of a calculator.

Greg used the calculator so much that he could be considered a calcumaniac.

calcumaniac by runekey February 20, 2009

calcomania 

recurrent urge to steal calculators that you generally do not really need

Sally has a real case of calcomania. She even took a calculator from Algebra class today.

calcomania by 7oaks September 22, 2016