Interesting Historical Facts

1. The number 10 is used as a convenient base to count with, but the Gauls of ancient France, the Mayas of Central America, and other peoples used a base of 20. The Sumerians, the Babylonians, and others after them used a base of 60—convenient because 60 can be evenly divided by 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30. The use of base 60 survives in the division of hours into minutes and minutes into seconds, and the division of the circle into 360 (60 × 6) degrees.

2. The earliest known unit of length was used around 2,300 B.C. by megalithic tomb builders in ancient Britain. The name of the unit is not known, but its length was about 2.72 feet

3. Euclid is the most successful textbook writer of all time. His Elements, written around 300 B.C., has gone through more than 1,000 editions since the invention of printing.

4. The modern decimal position system, in which the placing of numerals indicates their value (units, tens, hundreds etc.), was the invention of the Hindus, around 800 A.D. Their invention of the sign for zero greatly simplified arithmetic computation. By comparison, the Roman numeral system containing no zero was awkward.

5.A billion in America is different from a billion in Great Britain. An American billion is a thousand million (1,000,000,000), but a British billion is a million million (1,000,000,000,000). Most of the other names for large numbers are different in the U.S. and the U.K. I typically use the American names in this site.