Studying mathematics for the sake of mathematics, formulation of conjectures to model real life situations and indeed the application of mathematical knowledge has helped to improve insight about nature.

The advances in pure mathematics, natural sciences, engineering, medicine, finance and the social sciences has lead to the formulation of more practical problems requiring practical solutions. Some of these needed solutions however pose a great strain on the human numerical capacity, hence the need for calculators.

Antiquity supplied itself with a means to eliminate this strain on the human numerical capacity and indeed eliminate error in calculations. The first calculators were recognized as mere counting materials and devices; they were stones, pebbles, bones and the abacus.

It was not until the 17^{th} century that the term calculating machine or mechanical calculator became widespread. Wilhelm Schickard built the earliest modern attempt at a mechanical calculator. His mechanical calculator comprised Abacus made of Napier bones which performed multiplication and division operations and a dialed pedometer which performed addition and subtraction operations. However, he was not very successful.

Blaise Paschal was going to create a successful mechanical calculator called the Paschaline two decades later to help his father’s tax collector business. Other mechanical calculators like the Thomas Arithometer, the Comptometer and even Charles Babbage’s Automatic calculators, the Difference Engine and the Analytical engine (which basically modeled the computer system), also followed suit.

These inventions however notable were not very efficient due to high energy consumption, multiple clock cycles, size, cost, poor memory capacity and most of them still had challenging error margins.

To solve the problem of inefficiency, Electronic calculators were introduced. The increased efficiency of electronic calculators was made possible through the use of solid state materials. By early 1960s, the first microprocessor, ‘the Intel 4004’, was manufactured and used to produce electronic calculators. By the mid 1970s, transistors were integrated into electronic calculators. This change allowed for reduction in size and cost of electronic calculators. In addition, more problem-specific and field-specific electronic calculators were manufactured to serve users better. The new calculators have keypads for input, LCD displays, more efficient power sources, memory storage capacity, improved processing power and speed, improved readability and are relatively pocket friendly.

In truth, calculators today cannot be placed side by side with the calculators that were available 200 years ago. Even so, the advancements in the world today especially in STEM (Science, Technology, Engineering and Mathematics) and even the quickness of this present generation calls for improved efficiency of calculators still.

Calculators need to become more problem specific with the advances in various fields fully appreciated. Transistors have to be doubled to further reduce bulkiness and cost thus increasing the processing power of calculators by reducing the number of clock cycles significantly. The storage capacity of calculators need to be improved especially for programmable calculators. Displays, input and output methods could never stop getting better, these more or less change every couple of years, and calculators should not be left out. Even so, these improvements should not be done without taking into cognizance the purpose of such calculators because in the end, efficiency is measured by the quality of an intended output.