**Calculator**

Also check the scientific calculator.

** Need For a Calculator**

We know that Math is the toughest subject to everyone in this world. But for few math is their favorite one. This is because of the fact that they understand the login behind the math subject.

Since it is so difficult to calculate the numbers in math, people started to think on inventing something which will solve this long pending issue of calculation manually.

There is a high possibility of getting wrong calculation while doing manual calculation.

This is where the need for a machine arise and the result if the need is CALCULATOR.

Calculator is a simple electronic device that assists us in doing the basic math works like addition, subtraction, division and multiplication. Nowadays with the advancement in the technology, calculators can do complex arithmetic calculations also.

Lets see the historic pathway followed by the Calculators in the below chronological data.

1960 – First soled state Electronic calculator was created

1970s – Pocket sized calculators started ruling the market

**Interesting Fact : Busicom is the first company to develop the first microprocessor for the calculator – Intel 4004**

Initially calculator was used in the petroleum industry in a vast range. By the end of the 1970s era, the calculators was developed in such a way that it became a very affordable electronic device which everyone should have.

In the advancement in technology, the calculator has also advanced and is with so many new features nowadays. At present we have scientific calculators which can do trigonometric and statistical calculations.

1986, An estimated 41% of the world’s generally used Hardware was calculator.

2007, Only 0.05% of the world is seeing calculator as a mandatory tool or hardware.

**Design**

Scientific calculator displays of fractions and decimal equivalents

**Input**

The calculators have a keyboard with numbers from 0 to 9 and the basic math symbols like addition subtraction multiplication and division. Few calculators have 00, 000 also.

**Display output**

If the calculator is able to calculate the input value, then it will show you a answer. The answer is shown in the LED output display screen in the top of the device. If the calculator is not compatible to do calculation for bigger numbers, the screen may display a error message.

Few calculators have function to display the last entered numbers also.

**Memory**

Most of the calculators do not have any memory capacity. It simply forgets the last made calculations. Few of the scientific calculators can have a limited memory and it can save some numbers and formulas also.

###### Power source

Maximum calculators run with a power source from a Battery. Solar cell calculators are famous old models. most of these calculators have a power on button but do not have power off button. Nowadays we have calculators as an app in the mobile itself.

**Key layout**

The following keys are commonly used in most of the calculators. Only the way in which it is arranged will differ. Few calculators have the functional keys in the bottom. And in some calculators the functional keys are in the side. In some calculators the functionsal keys are in the top of the keyboard and below the display.

**Usual basic pocket calculator layout**