Step inside any high-school math class in the United States, and chances are you’ll find students staring down at their Texas Instrument calculators, nimbly typing commands into those $100 pocket computers. Calculators are so commonplace in modern American education that a TI-84 or -89 can be found stashed away in many homes, mementos from taking the SAT or computing integrals on the Advanced Placement calculus exam.

Still, college professors remain divided on the use of calculators in their classes. When I took my freshman math courses at McGill University in Montreal last school year, I had to revert back to pencil and paper, clumsily lining up columns to do addition and long-multiplication problems at my professor’s request. This isn’t an unusual predicament: According to a 2010 national survey by the Mathematical Association of America, nearly half of Calculus 1 college instructors prohibit students from using graphing calculators on exams.

The debate over the use of calculators in math classrooms has ensued for more than four decades—nearly as long as the contemporary calculator has been around. Although the abacus has been in use since the time of the Sumerians and Ancient Egyptians, it wasn’t until 1958 when the Texas Instrument engineer Jack Kilby invented the integrated circuit, which paved the way for the cheap and compact computer chips used in most electronic devices today. (Kilby later won the Nobel Prize in physics.) A decade later, calculators would no longer be stored in gigantic cabinets with a price tag of over $700,000; they would substantially diminish in size and gradually become more affordable. Today, prices for graphing calculators hover around $80.