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Calculator

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A calculator is a portable electronic device used for math.

Casio calculator JS-20WK in 201901 002
Casio calculator JS-20WK in 201901 002

People use them for everything from simple sums to very hard math. Some models are small enough to fit in a pocket. Other models are large desktop tools that can even print results on paper.

Tischrechner Walther ETR2034S resized
Tischrechner Walther ETR2034S resized

There are also special kinds made for specific jobs. Scientific calculators can do trigonometry or statistics. Graphing calculators can draw shapes on a screen. Most people today use calculator programs on their smartphones or tablets.

How does a calculator work when you press a button?

Interior of a calculator
Interior of a calculator

First, a scanning unit looks for an electrical signal from the keypad. When you press a number, that number is sent to a temporary storage area called a register. If you press a second number, the first one moves to another register. The calculator also remembers the math command, like addition, in a flag register. Then, a part called the arithmetic logic unit (ALU) takes these numbers and follows instructions to find the answer. Finally, the result is sent to the display panel so you can see it.

Humans have used many tools to help with math for a long time.

17th-century-mechanical-calculators
17th-century-mechanical-calculators

Before electronics, people used bones, pebbles, or an abacus to count. In the 1600s, inventors like Wilhelm Schickard and Blaise Pascal made mechanical calculators with moving parts. The first solid-state electronic calculators were created in the early 1960s. In the 1970s, pocket-sized devices became available for more people. This happened because of the Intel 4004, which was the first microprocessor. This tiny chip was made for a Japanese company called Busicom.

Calculators come in many different styles and sizes.

Fx-991EX
Fx-991EX

Most modern pocket calculators use liquid-crystal displays, or LCDs, to show numbers. Some older models used light-emitting diodes (LEDs) or vacuum fluorescent displays (VFDs). Most calculators get their power from batteries or solar cells.

Solar-calculator
Solar-calculator

Some very large models plug into mains electricity from a wall. In 1986, calculators were used for about 41% of the world's computing work. By 2007, that number dropped to less than 0.05% because of newer technology.

Many parts of a calculator are things you might already know.

CalculatorFractions-5550x
CalculatorFractions-5550x

The buttons on a calculator are arranged in a specific way. This layout is actually very similar to how old cash registers were set up. It is different from a telephone keypad, which has numbers in different spots. You might also notice that calculators use a decimal point to show parts of a number. Some scientific models can even show fractions as mixed numbers. These tools help us turn hard math problems into quick and easy answers.

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🖼️ Images & Media (19)
File:Casio calculator JS-20WK in 201901 002.jpg
Casio calculator JS-20WK in 201901 002.jpg
File:Fx-991EX.jpg
Fx-991EX.jpg
File:CalculatorFractions-5550x.jpg
CalculatorFractions-5550x.jpg
File:Interior of a calculator.jpg
Interior of a calculator.jpg
File:Tischrechner Walther ETR2034S resized.jpg
Tischrechner Walther ETR2034S resized.jpg
File:17th-century-mechanical-calculators.jpg
17th-century-mechanical-calculators.jpg
File:Grant mechanical calculating machine 1877.jpg
Grant mechanical calculating machine 1877.jpg
File:EdithClarkeCalculatorUSPatentDrawing.png
EdithClarkeCalculatorUSPatentDrawing.png
File:LED DISP.JPG
LED DISP.JPG
File:Elka-22 (I197211).png
Elka-22 (I197211).png
File:Olivetti Programma 101 - Museo scienza e tecnologia Milano.jpg
Olivetti Programma 101 - Museo scienza e...
File:Casio as-a ckt1 1c.jpg
Casio as-a ckt1 1c.jpg

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