Top 10 numbers factsNumbers quiz
Which number is considered unlucky in East Asia? 4
Words "four" and "Death" have very similar pronunciation in Chinese, Vietnamese, Korean and Japanese. In East Asia many buildings do not have a 4th floor. Some high-rise residential buildings omit all floor numbers with "4", e.g., 4, 14, 24, 34 and all 40–49 floors.
Which numeral system was in use in ancient Sumer and Babylon? Sexagesimal.
Remnants of the highly composite sexagesimal system are in use even today for time measurement and geometry. An hour of time is divided into 60 minutes, which in turn are divided into 60 seconds.
What’s the distance between Russia and the U.S. at their closest point? 4 km (2.5 miles).
Although the Strait’s narrowest point is about 53 miles (85 km) wide, there are two islands in its center, Little Diomede (U.S.) and Big Diomede (Russia), which bring the distance of these two nations only 2.5 (4 km) miles apart at their closest point.
Which number is the Avogadro constant? 6.022 × 1023 mol-1.
Avogadro's number, number of units in one mole of any substance (defined as its molecular weight in grams), equal to 6.022140857 × 1023. The units may be electrons, atoms, ions, or molecules, depending on the nature of the substance and the character of the reaction.
Typically, how many leap years are in a century? 24.
The Gregorian Calendar omits 3 leap days every 400 years, omitting February 29 in the 3 century years (integer multiples of 100) that are not also integer multiples of 400. For example, 1600 was a leap year, but 1700, 1800 and 1900 were not. Similarly, 2000 was a leap year, but 2100, 2200, and 2300 will not be.