The very first calculator was a Pascaline adding and subtracting machine created by Pascal in 1642, so calculators have been around for a long time - almost 400 years. The interesting connection with Pascal's calculator is little has changed since then, as far as how numbers are calculated. The difference today is the speed and variety computations that can be completed with a calculator.

The golden age of calculators began in the 1800's. Technological and mechanical challenges were faced by all those who developed early calculators. These limitations often caused early calculators to not function correctly, if at all. However, in the 1800's technological and mechanical capabilities had advanced enough for reliable mechanical calculators to be built and operated. Some of these included:

- In 1820, the Arithmometer was developed by Colmar which used a step drum technique to add, subtract, multiply, and divide.
- In 1875, the Original Odhner was developed by Odhner who invented a pinwheel or variable cog calculator which used a hand crank to complete the computation.
- In 1885, the Comptometer was developed by Felt who invented the first calculator using keys to push for number entry and calculations.

In the 1900's the golden age of calculators continued and began taking on the familiar shape we use today.

- In 1901, the Standard calculator was developed by Hopkins who used two rows of five buttons representing the digits 0 through 9 to perform math computations.
- In 1911, the standard ten digit keyboard we use today was developed by Sundstrand who brought the design from Sweden to the United States.
- In 1914, the first commercial calculators began entering businesses and the use of calculators began to be popular.

The golden age of calculators continued until the 1960's, since they were mechanical devices requiring the entering numbers in specific sequences to accomplish the desired mathematical computation. Most even had the mechanical handle you pulled during various parts of the computations to eventually wind up with the desired result.

In the 1960's everything began to change as soon as transistors and other technological components could be made small enough to fit in portable calculator devices. The first electronic calculators began to appear:

- In 1961 the Anita MK8 was developed using 170 vacuum tubes coupled to a decade counter, for basic math operations and was used to display numbers in a desktop calculator.
- In 1964 the Sharp Compet CS 10A was developed as the first transistor commercial calculator.
- In 1968 the Sharp Compet 22 was placed on the market as the first desk top commercial electronic calculator.
- In 1969 the Sharp QT8-D was introduced as the first battery operated hand held calculator. It was only 5.2 inches wide, 9.6 inches tall, and 2.75 inches thick. This was a major achievement in the 1960's.
- In 1970 the first Texas Instrument calculator, called the Pocketronic, was developed and was even smaller than the Sharp QT8-D.

Calculators continued to evolve and became smaller and more sophisticated in their ability complete complex computations.

- In 1975 the HP-55 by Hewlett Packard was introduced for a price of $385.00.

From the 1970's through to 1990 a market war was waged by many companies trying to enter the handheld calculator business. In 1990 there were only four major companies left:

- Casio
- Texas Instruments
- Hewlett Packard
- Sharp

Beginning in the 1990's through today, the number of handheld calculators has exploded onto the market. They include graphing calculators and specialty scientific calculators. Due to the technological advances, the price of calculators has decreased significantly. The first calculators built in the 1600's, 1700's, and 1800's which could just simply do the four basic math computations would cost thousands of dollars today. Today you can get a calculator that completes these same basic functions for less than a dollar.

Calculators have come a long way through the technological evolution stages; the question is what will they look like 400 years from now?