When were Arabic numerals invented?

When were Arabic numerals invented?

They were developed in India by the Hindus around 600 A.D. Interestingly, these numbers were written “backwards”, thus one hundred twenty three was written 321. Around 750 A.D. this system of decimal arithmetic was brought to Persia when several important Hindu works were translated into Arabic.

How high is the golden gate bridge above the water?

The Golden Gate Bridge’s clearance above high water averages 220 feet (67 m) while its towers, at 746 feet (227 m) above the water, were the world’s tallest on a suspension bridge until 1998 when bridges in Denmark and Japan were completed.

What percent of the population has 20 20 vision?

Only about 35 percent of all adults have 20/20 vision without glasses, contact lenses or corrective surgery. With corrective measures, approximately 75 percent of adults have this degree of visual acuity while the other 25 percent of the population just doesn’t see very well, Dr. Johnson says.

Who was the first Renaissance artist to use oil paints?

Most Renaissance sources, in particular Vasari, credited northern European painters of the 15th century, and Jan van Eyck in particular, with the “invention” of painting with oil media on a wood panel support (“support” is the technical term for the underlying backing of a painting).

What was Uncle Sam’s real name?

On this day in 1813, the United States gets its nickname, Uncle Sam. The name is linked to Samuel Wilson, a meat packer from Troy, New York, who supplied barrels of beef to the United States Army during the War of 1812.

How many shipwrecks are on the ocean floor?

The United Nations estimates that there are over three million shipwrecks on the ocean floors. Lost, destroyed, or deliberately sunk, these wrecks are of interest to divers, underwater archaeologists, and treasure hunters alike.

How many chambers are in a dog’s heart?

A dog’s heart is divided into four chambers. The two top chambers are called the atria (single: atrium) whereas the bottom chambers are called the ventricles.

Which is the highest mountain peak in the world?

Mount Everest is called the world’s highest mountain because it has the highest elevation above sea level. We could also say that it has the “highest altitude”. The peak of Mount Everest is 8,850 meters (29,035 feet) above sea level.