Some people dont know what is billion... let me explain! 
1,000,000,000 (one billion, short scale) is the natural number following 999,999,999 and preceding 1,000,000,001.
In scientific notation, it is written as 109.
In modern (short scale) English language usage, it is usually called a billion (although in many other languages and long scale usage, a billion means a million millions, or 1,000,000,000,000, instead of a thousand millions).
In Indian English, it may be known as 100 crore.
The term milliard can also be used to refer to 1,000,000,000, though this terminology is rarely used in the English language, but often in other languages.
Physical quantities can be expressed using the SI prefix giga.
See Orders of magnitude (numbers) for larger numbers; and long and short scales.
[edit] Selected 10-digit numbers (1000000000 - 9999999999)
* 1023456789 - smallest pandigital number in base 10
* 1026753849 - smallest pandigital square, including 0
* 1073676287 - 15th Carol number
* 1073741824 = 230
* 1073807359 - 14th Kynea number
* 1129760415 - 23rd Motzkin number
* 1134903170 - 45th Fibonacci number
* 1162261467 = 319
* 1220703125 = 512
* 1234567890 - pandigital number with the digits in order
* 1311738121 - 25th Pell number
* 1382958545 - 15th Bell number
* 1406818759 - 30th Wedderburn-Etherington number
* 1836311903 - 46th Fibonacci number
* 1977326743 = 711
* 2147483647 - 8th Mersenne prime and the largest signed 32-bit integer
* 2147483648 = 231
* 2214502422 - 6th primary pseudoperfect number
* 2357947691 = 119
* 2971215073 - 11th Fibonacci prime (47th Fibonacci number)
* 3166815962 - 26th Pell number
* 3192727797 - 24th Motzkin number
* 3323236238 - 31st Wedderburn-Etherington number
* 3486784401 = 320
* 4294836223 - 16th Carol number
* 4294967291 - Largest prime 32-bit unsigned integer
* 4294967295 - Maximum 32-bit unsigned integer (hexadecimal FFFFFFFF)
* 4294967296 = 232
* 4294967297 - the first composite Fermat number
* 4295098367 - 15th Kynea number
* 4807526976 - 48th Fibonacci number
* 5784634181 - 13th alternating factorial
* 6210001000 - only self-descriptive number in base 10
* 6227020800 = 13!
* 6983776800 - 15th colossally abundant number
* 7645370045 - 27th Pell number
* 7778742049 - 49th Fibonacci number
* 7862958391 - 32nd Wedderburn-Etherington number
* 8589869056 - 6th perfect number
* 8589934592 = 233
* 9043402501 - 25th Motzkin number
* 9814072356 - largest square pandigital number, largest pandigital pure power
* 9876543210 - largest pandigital number without redundant digits
1 billion is equal to one thousand million.
[edit] Sense of scale
The facts below give a sense of how large 1,000,000,000 (109) is in the context of time according to current scientific evidence:
* 109 seconds is about 31.7 years.
* About 109 minutes ago, the Roman Empire was flourishing. (109 minutes is roughly 1,900 years.)
* About 109 hours ago, modern human beings and their ancestors were living in the Stone Age (more precisely, the Middle Paleolithic). (109 hours is roughly 114,000 years.)
* About 109 days ago, Australopithecus, an ape-like creature related to an ancestor of modern humans, roamed the African savannas. (109 days is roughly 2.7 million years.)
* About 109 months ago, dinosaurs walked the earth during the late Cretaceous. (109 months is roughly 82 million years.)
* About 109 years ago, the first multicellular organisms appeared on Earth.
* The universe is currently thought to be about 13.7 × 109 years old.
In terms of distance:
* 109 centimetres is about the distance from Chicago to Tokyo.
* 109 inches is 15,783 miles, more than halfway around the world and sufficient to reach any point on the globe from any other point.
* 109 metres is almost three times the distance from the Earth to the Moon.
* 109 kilometres is over six times the distance from the Earth to the Sun.
In terms of finance:
* The possession of 109 United States dollars would place a person among the world's wealthiest individuals.
In terms of count:
A is a cube; B consists of 1000 cubes of type A. C consists of 1000 Bs; and D 1000 Cs. Thus there are 1 million As in C; and 1,000,000,000 As in D. Likewise, there are 1,000,000,000 cubic millimetres in a cubic metre.
President Mahinda Rajapakse today accepted the challenge thrown by UNP leader Ranil Wickremesinghe for an open debate and said both can debate at Galle Face with the participation of the public after President Rajapakse sorted out a few burning issues of the country.
