Scientific calculator

They have completely replaced slide rules as well as books of mathematical tables and are used in both educational and professional settings.

Standalone scientific calculators remain popular in secondary and tertiary education because computers and smartphones are often prohibited during exams to reduce the likelihood of cheating.

[1] When electronic calculators were originally marketed they normally had only four or five capabilities (addition, subtraction, multiplication, division and square root).

They are very often required for math classes from the junior high school level through college,[3] and are generally either permitted or required on many standardized tests covering math and science subjects;[4] as a result, many are sold into educational markets to cover this demand, and some high-end models include features making it easier to translate a problem on a textbook page into calculator input, e.g. by providing a method to enter an entire problem in as it is written on the page using simple formatting tools.

The HP-9100 series was built entirely from discrete transistor logic with no integrated circuits, and was one of the first uses of the CORDIC algorithm for trigonometric computation in a personal computing device, as well as the first calculator based on reverse Polish notation (RPN) entry.