To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
.
Leo
Newton
Brights
Milds

# 20 (number)

 ← 19 20 21 →
Cardinaltwenty
Ordinal20th
(twentieth)
Numeral systemvigesimal
Factorization22× 5
Divisors1, 2, 4, 5, 10, 20
Greek numeralΚ´
Roman numeralXX
Binary101002
Ternary2023
Quaternary1104
Quinary405
Senary326
Octal248
Duodecimal1812
Vigesimal1020
Base 36K36

20 (twenty) is the natural number following 19 and preceding 21. A group of twenty units may also be referred to as a score.[1][2]

• 1/5
Views:
3 043
2 872 981
1 858 191
4 578
10 106
• ✪ BIRTH DATE 20#SECRET OF 20 BIRTH DATE#NUMEROLOGY NUMBER 20#20 NUMBER NUMEROLOGY READING
• ✪ Number Song 10-20 | Counting from 10-20 | The Singing Walrus
• ✪ Counting Numbers | Numbers 1-20 Lesson for Children
• ✪ "20" Number song
• ✪ Addition and Subtraction facts to 20 - Number Bonds to 20

## In mathematics

An icosahedron has 20 faces

## In science

### Biology

• The number of proteinogenic amino acids that are encoded by the standard genetic code.
• In some countries, the number 20 is used as an index in measuring visual acuity. 20/20 indicates normal vision at 20 feet, although it is commonly used to mean "perfect vision". (Note that this applies only to countries using the Imperial system. The metric equivalent is 6/6.) When someone is able to see only after an event how things turned out, that person is often said to have had "20/20 hindsight".

## As an indefinite number

• A 'score' is a group of 20 (often used in combination with a cardinal number, i.e. fourscore to mean 80), but also often used as an indefinite number[7] (e.g. the newspaper headline "Scores of Typhoon Survivors Flown to Manila")[8]

## In sports

A standard dartboard is laid out as 20 sectors

## References

1. ^ John H. Conway and Richard K. Guy, The Book of Numbers. New York: Copernicus (1996): 11. ""Score" is related to "share" and comes from the Old Norse "skor" meaning a "notch" or "tally" on a stick used for counting. ... Often people counted in 20s; every 20th notch was larger, and so "score" also came to mean 20."
2. ^ [1]
3. ^ "Sloane's A000292 : Tetrahedral numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-31.
4. ^ "Sloane's A071395 : Primitive abundant numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-31.
5. ^ "God's Number is 20". Cube20.org
6. ^ Jonathan Fildes (August 11, 2010). "Rubik's Cube quest for speedy solution comes to an end". BBC News.
7. ^ "Biblical Criticism", The Classical Journal 36:71:83ff (March 1827) full text
8. ^ "CBS News", Scores of Typhoon Survivors Flown to Manila (November 2013) [2]
9. ^ "Japan's Age of Majority Changed to 18  - Living the Japon.com". www.japan-experience.com. Retrieved 19 March 2018.