The slide rule is used primarily for multiplication and division, and also for functions such as exponents, roots, logarithms, and trigonometry, but typically not for addition or subtraction.

Subsequently, What is a slide rule calculator?

Before the smartphone, the laptop and the graphing calculator, there was the slide rule. It’s a powerful mechanical computing device, often no larger than a 12-inch ruler, marked with numbers â€” but part of it slides in an out to to show relationships between different sets of numbers.

Also, How much is a slide rule worth?

The rarest slide rules are 19th Century hand-engraved instruments such as Palmers Computing Scale (a circular model), first published in 1843, or the cylindrical ‘Thacher’s Patent Calculating Instrument’ slide rules produced by Keuffel and Esser Co in the 1880s. These can run close to \$1,000 in good condition.

What is the purpose of a slide rule?

To serve as a mechanical analog computer

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## Who made the best slide rules?

Scottish theologian John Napier laid the foundation for the invention of the slide rule in 1614 with the invention of logarithms. In 1622, the mathematician William Oughtred set two straight edges marked with logarithmic scales side by side and created the first rectilinear slide rule.

## How accurate is a slide rule?

A slide rule is only as accurate as its manufacture and calibration and your ability to set it and read values. In practice, you get between two and three significant figures from slide rule calculations, and these errors compound as you use intermediate values in subsequent calculations.

## Are slide rules collectible?

Early slide rules were made of wood and celluloid, while later ones tended to be plastic or metal. … There are straight, circular and cylindrical slide rules, all collectible. Major manufacturers included Keuffel and Esser, Pickett, Gilson, Dietzgen, Post (which became Teledyne), Faber-Castell, Aristo, and others.

## How do you create a slide rule?

– Take an ordinary ruler, and put decimal points before the numbers marking the inches. …
– To position the major (black) divisions on the logarithmic scale, calculate the base-10 logarithm of each integer from 2 to 9 and plot the integer at that place on the ruler.

19th century

## Are slide rules still used?

The use of slide rules continued to grow through the 1950s and 1960s even as computers were being gradually introduced; but around 1974 the handheld electronic scientific calculator made them largely obsolete and most suppliers left the business.

## What professions use the slide rule?

NASA engineers used slide rules to build the rockets and plan the mission that landed Apollo 11 on the moon. It’s said that Buzz Aldrin needed his pocket slide rule for last-minute calculations before landing.

## Are old slide rules Valuable?

By the end of the 1970s, all the slide rule manufacturers died. … So there were several models sold that had a math calculator on one side and a slide rule glued to the back to do those other functions. Those are worth a lot of money if you’re collecting.

## Is the slide rule still used today?

Slide rules are still commonly used in aviation, particularly for smaller planes. They are being replaced only by integrated, special purpose and expensive flight computers, and not general-purpose calculators. … Some wrist watches designed for aviation use still feature slide rule scales to permit quick calculations.

## Does anyone use a slide rule anymore?

The use of slide rules continued to grow through the 1950s and 1960s even as computers were being gradually introduced; but around 1974 the handheld electronic scientific calculator made them largely obsolete and most suppliers left the business.

## Are slide rules still made?

Though they’re no longer produced, the company still stocks around 1,200 or so and occasionally gets an order for some. Why would anyone still want to buy a slide rule, when inexpensive calculators are so readily available? According to Haase, slide rules are better suited to some functions than are calculators.Apr 7, 1987

## On what principle does slide rule work?

A slide rule works by adding or subtracting the numerical exponents of numbers for multiplication or division, respectively. Thus, numbers to be multiplied or divided are converted to their logarithmic values and their exponents are added or subtracted.