Basic Calculator

Basic calculator

Our free online calculator allows you to perform standard mathematical operations quickly and efficiently. This versatile basic calculator supports the following functions:

• addition,
• subtraction,
• multiplication,
• division,
• raising to the power of 2,
• taking a square root,
• identifying, adding, and subtracting a percentage.

This tool accepts both integers and decimal numbers as inputs. While the fundamental operations listed above are often easy to perform mentally, a simple online calculator is incredibly handy for handling large numbers and complex decimals with precision.

Directions for use

To maximize your efficiency, familiarize yourself with the special commands included in this digital calculator:

• mc stands for "Memory Clear." Press this button when you want to erase all data currently saved in the calculator's memory.

• mr stands for "Memory Recall." Press it to retrieve the number currently stored in the calculator's memory. If the memory is empty, mr will simply return a zero.

• m- stands for "Memory Minus." Pressing this button subtracts the number currently displayed on your screen from the number stored in the calculator's memory.

• m+ stands for "Memory Plus." Similar to m-, pressing m+ adds the number currently on the screen to the existing value stored in the calculator's memory.

• C.E. stands for "Clear Entry" and is used to remove your current input. Note that this button only becomes visible after you have made at least one entry and the screen is no longer empty.

• A.C. stands for "All Clear." Press this button when you want to delete all previous entries in your current calculation. For example, if you are trying to calculate 8-3=? but accidentally enter 8-4, you can press C.E. before hitting the = sign. This will delete only the last entry (4) while keeping your first entry (8) intact. You can then press 3 and hit the = sign to get the correct answer. In contrast, hitting A.C. deletes all inputs, including the 8. Keep in mind that hitting A.C. does not clear the calculator's memory; you must press mc to do that.

• R2 stands for "Round to 2 decimals." If a calculation leaves you with a long string of decimals, such as 3.98124567, pressing R2 will round it to a cleaner, simpler number. In this case, it becomes 3.98.

• R0 stands for "Round to 0 decimals." Using the previous example, pressing R0 rounds 3.98124567 to the nearest whole number, resulting in 4.

If your calculations result in an exceptionally large or microscopically small number, the calculator will automatically use scientific e-notation to display the answer. For example, if the result is 0.00000007, the calculator will display 7e-8, which represents 7×10⁻⁸.

Calculating percentages

When determining the percentage of a specific number, pressing the % sign will automatically convert the percentage value into a decimal. For example, if you need to find 20% of 75, you should enter 75 × 20%. Pressing the % sign will automatically change the 20 to 0.2. To see the final result, simply press the equal sign, which will display 15 (since 15 is 20% of 75).

This calculator also allows you to easily add or subtract a specific percentage directly from a base value. For instance, suppose you want to calculate 60 - 15%. After you enter 60 - 15 and press the % sign, the 15 will automatically convert to 9, because 9 is 15% of 60. Once you press the equal sign, you will receive your final answer: 51.

Calculation examples

Taxation

This tool is incredibly useful for quickly calculating sales tax. Let's say you want to find the total purchase price of an item that costs $567 with a 6% sales tax. Enter 567 + 6% and press the equal sign. The moment you hit the % sign, you will see the exact monetary value of the sales tax applied to this purchase (34.02). After pressing the equal sign, the screen will display the final total: 601.02.

Sometimes, a final calculation will leave you with more than two digits after the decimal point. In such cases, you can press R2 to instantly round the result to two decimals, giving you a clean final price in dollars and cents.

For example, if the sales tax in our previous scenario was 6.6% instead of 6%, the calculated tax value would be 37.422, and the final answer would be 604.422. To find the exact value in dollars and cents, press R2. The screen will return 604.42, meaning your total purchase price is 604 dollars and 42 cents.

Calculating the area of a house

Let's assume you need to calculate the total floor area of your house to figure out how many floor panels to buy. You have two rooms: the first is 5 meters long and 3 meters wide, and the second is 4 meters long and 6 meters wide. As a reminder, the area of a room is calculated using the following formula:

Area = Length × Width

Instead of calculating the two areas separately and writing them down before adding them together, you can use the calculator's memory functions to do everything in one seamless sequence. First, enter 5 × 3 =, which gives you 15 (the area of the first room). Then, press m+ to store this number in the calculator's memory. Next, enter 4 × 6 =, yielding 24 (the area of the second room).

With 24 still displayed on the screen, press the plus sign + followed by mr to recall the stored value (15) from memory. Finally, press the equal sign to get the total: 39. The combined area of both rooms is 39 square meters.

Calculator: the history of development

The word "calculator" originates from the Latin calculo, meaning "to count" or "to calculate." It is also closely linked to the word calculus, which translates to "pebble." In ancient times, before the invention of complex tools, people relied on pebbles to perform basic arithmetic.

Abacus

Invented in ancient Babylon around the 3rd millennium B.C., the abacus served as the world's earliest prototype of a counting machine.

Initially, the abacus was simply a board ruled into lines or carved with indentations. Counting marks, such as stones or dice, were moved along these lines. Over time, the abacus evolved into a framed device where pebbles or specially carved bones were threaded onto rods.

When a user moved all the pebbles on the first rod to one side, a single pebble on the adjacent rod would be shifted, representing the tens column. The next rod represented hundreds, and so on (meanwhile, the tenth pebble in the first row was reset to its original position).

Variations of the abacus remained highly relevant for centuries. In fact, counting frames were still widely used for bookkeeping and settling store accounts in some parts of the world well into the 1980s and 1990s.

The Antikythera mechanism

Discovered in a shipwreck off the Greek island of Antikythera in the early 20th century, the Antikythera mechanism is widely considered one of the oldest ancestors of the modern calculator. Scientists believe this intricate bronze mechanism dates back to the second century B.C. While it was primarily used to calculate and predict the complex motion of planets and satellites, the Antikythera mechanism could also add, subtract, and divide numbers.

Leonardo da Vinci's counting machine

Within the diaries of Leonardo da Vinci lie the drawings of the very first mechanical calculating machine. Da Vinci's design featured a series of rods connected by wheels of varying sizes. Each wheel was equipped with specialized cogs to drive the mechanism. Ten rotations of the first wheel would trigger one full rotation of the second wheel, and ten cycles of the second wheel resulted in a complete rotation of the third. Unfortunately, Da Vinci was never able to build a working prototype during his lifetime.

Schickard's calculating clocks

In 1623, German professor Wilhelm Schickard designed what he called a "calculating clock," earning its name due to the complex internal gears similar to those found in timepieces. Schickard's invention was groundbreaking; it was the first mechanical device capable of performing all four fundamental arithmetic operations: addition, subtraction, multiplication, and division.

Blaise Pascal's counting machine

In 1642, a 19-year-old Blaise Pascal began developing a new calculating machine. Pascal's father was a tax collector who faced endless manual arithmetic, so the young inventor created a device to ease his father's workload.

Pascal's calculator was housed in a small box containing a complex network of interconnected gears. Users entered the numbers needed to perform arithmetic operations by carefully turning the dials. Over a ten-year span, Pascal built roughly 50 prototypes of his machine, eventually selling 10 of them.

Leibniz’s calculator

In 1673, the renowned German mathematician Gottfried Wilhelm Leibniz created his own version of a mechanical calculator. While it shared the foundational gear-and-wheel logic of Pascal's machine, Leibniz introduced a massive innovation: a stepped cylinder known as the Leibniz wheel.

Although Leibniz's initial device suffered from some mechanical flaws, it revolutionized the trajectory of calculating technology. The stepped cylinder he invented became a core component in many calculating devices for the next 200 years.

The Colmar Arithmometer

In the first half of the 19th century, Charles Xavier Thomas de Colmar created the Arithmometer. Heavily inspired by Wilhelm Leibniz's design, this device became the first commercially successful mechanical calculator.

The De Colmar Arithmometer was a sturdy, compact iron or wooden mechanism featuring an automated counter. Capable of handling addition, subtraction, multiplication, and division, this impressive machine could process numbers up to thirty digits long. Production of the Arithmometer lasted for over 60 years (until 1915), and it was manufactured and sold by more than 20 different companies globally.

Calculators in the XX Century

In the late 1930s, as the world braced for another global conflict, militaries desperately required advanced mathematical precision for aiming artillery and anti-aircraft guns.

One of the first devices created to control anti-aircraft fire was the Kerrison predictor. This mechanical counting device could rapidly calculate the precise pointing angle for guns by analyzing the target's position, ballistic parameters, wind speed, and other real-time variables.

During World War II, the British developed Colossus, the world's first fully electronic computer, to decode intercepted enemy communications. Though strictly specialized for cryptography, it was programmable and even featured an electronic display.

Shortly after the war ended in the fall of 1945, ENIAC was completed. Originally designed to calculate complex artillery firing tables for the military, it could also perform the four basic arithmetic functions. The ENIAC was 1,000 times faster than prior electromechanical computers and possessed enough memory to store ten-digit numbers. Operating it was no small feat; it required 17,468 electronic vacuum tubes, 7,200 crystal diodes, 1,500 relays, 70,000 resistors, 10,000 capacitors, and roughly 5 million hand-soldered connections.

Weighing roughly 27 tons and occupying 167 square meters of space, ENIAC remained in operation until 1955 at the U.S. Army Ballistics Research Laboratory.

By 1961, the British company Control Systems Ltd. introduced ANITA, the world's first fully electronic desktop calculator. It utilized vacuum tubes for its internal calculations and glowing gas-discharge indicators for its display. These early ANITA models sold for approximately £355—which equates to about £4,800 ($8,000) in today's currency.

Soon after, major tech companies like Canon, Mathatronics, Olivetti, SCM (Smith-Corona-Marchant), Sony, Toshiba, and Wang entered the fiercely competitive calculator market.

In 1965, Wang Laboratories released the Wang LOCI-2, a calculator distinctively designed with a logarithm calculation function. That same year, the Toshiba "Toscal" BC-1411 utilized one of the earliest forms of RAM, constructed entirely from circuit boards. Late 1965 also saw the debut of the Olivetti Programma 101, which could read and write data on magnetic cards and print calculation results directly from a built-in printer.

Meanwhile, the ELKA 22 calculator was developed by the Central Institute for Computing Technology in Bulgaria. Weighing a hefty 8 kilograms, it held the distinction of being the world's first calculator capable of extracting square roots.

The race toward miniaturization took a massive leap in 1967 when Texas Instruments unveiled the Cal Tech prototype. It could add, subtract, multiply, divide, print results on paper tape, and astonishingly, fit perfectly in the palm of a hand. Decades later, in 1985, Casio released the Casio FX-7000G. Equipped with 82 scientific functions and full programmability, it is widely celebrated as the world's first publicly available graphing calculator.

Contemporary Calculators

By the end of the 21st century's first decade, numerous companies were mass-producing hundreds of calculator models tailored for highly specific purposes. CASIO remains a reigning global leader in calculator production, notably announcing the milestone of its one billionth calculator sold in 2006.

Today, we have instantaneous access to a vast array of calculators. Depending on their specialized features and target audience, they are categorized into basic, engineering, accounting, and financial calculators. Modern physical calculators are powerful enough to run complex, pre-built programs directly from their hardware.

Thanks to modern programming languages, developers can now create highly specialized web-based calculators and make them freely available on the Internet. Whether you need a mathematical, engineering, statistical, medical, fitness, financial, time, or conversion calculator, these powerful online tools are now just a click or a tap away on your computer or smartphone.