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WikiCards · Card list · Science cards · Cardinal number
Uncommon card · Science
Cardinal number, an Uncommon card
In mathematics, a cardinal number, or cardinal for short, is a kind of number that measures the cardinality of a set, i.e., how many elements there are in a set.
- Rarity
- Uncommon
- Domain
- Science
- ATK
- 72
- DEF
- 54
- Power
- 126
- Wikipedia reads a year
- 79,000
Power 126 (ATK + DEF): stronger than 60 % of WikiCards cards.
Cardinal number quiz: 3 questions
Three questions on the Cardinal number card, the way WikiCards duels ask them. Pick an answer, the facts are just below.
Find the missing word
The ______ of a finite set can be identified with a natural number, which can be found simply by counting its elements.
Answer
cardinality. The cardinality of a finite set can be identified with a natural number, which can be found simply by counting its elements. From the Cardinal number article on Wikipedia.
Which of these Wikipedia articles is read the most in a year?
Answer
Sky. Sky 140,000 · Combine harvester 110,000 · Cardinal number 79,000 · Omega Centauri 55,000 Wikipedia reads over a year.
In a duel, each round asks a question like these about the opposing card, with 15 seconds to answer.
The facts on the card
The card carries these facts from its Wikipedia article.
- The cardinal number associated with a set A is generally denoted by | A | , with a vertical bar on each side, though it may also be denoted by A, card , or # A. Cardinality is defined in terms of bijective functions.
- Two sets have the same cardinality if, and only if, there is a one-to-one correspondence between the elements of the two sets.
- The cardinality of a finite set can be identified with a natural number, which can be found simply by counting its elements.
Why it is Uncommon
Rarity in WikiCards follows a year of Wikipedia page views: the most read articles become Epic and Legendary cards. The Cardinal number article was read about 79,000 times in a year. ATK comes from the length of the article and DEF from its quality, so this card hits with 72 and blocks with 54: each hit it takes is cut by 22 %.
How to get Cardinal number
Open packs. Each pack holds five cards drawn from real Wikipedia articles, the rarest last, and the fifth card is always Rare or better. The odds are shown in the game. A free pack arrives every hour and two can wait, and the Coins you win in duels buy more packs.
More Science cards
Cards close in power
The cards just above and just below Cardinal number in the power ranking, all domains together.
- Brayton cycleUncommon · History · ATK 67 DEF 59
- Book of EzraUncommon · Arts · ATK 68 DEF 58
- OrthopteraUncommon · Nature · ATK 64 DEF 62
- Dried fruitUncommon · Society · ATK 66 DEF 60
- Jean RacineUncommon · Arts · ATK 76 DEF 50
- Johnson Aguiyi-IronsiUncommon · History · ATK 66 DEF 60
Card lists
- Wikipedia quizNew questions every day
- All cards from A to ZEvery card, by name
- Science cards
- Legendary cards
- Tier listS and A tiers by power (ATK + DEF)
Credits
Text : Wikipedia, Cardinal number (revision), CC BY-SA 4.0. Photo : Schapel, Public domain, Wikimedia Commons.
