×, commonly code-named U+00D7, is called "multiplication sign", also known as "cross" or "cross". There are the following possible usages and meanings:
English: Numbers hidden in punctuation marks are used to replace inconvenient words.
Mathematics: multiplication symbol in four operations, used in operations:
Product of multiplication
The cross product of a vector, as opposed to the dot product.
Cartesian product of sets
Biology: Representing the hybridization of two species in the genetic map.
Popular culture: used to express the intersection of two unrelated people, concepts, works, etc. , which is now called "cross-border".
Japanese: It is called "ばつ" (penalty), "ばってん" (penalty spot) or "ぺけ" (? ), which means incorrect and unequal. , as opposed to ○: "まる" (pill, circle)
Fan and other literary works. : Used to replace "parameters" that need to exist but do not need to be clearly stated, and often shared with "○", □ "and △" * * * ". For example:
The date on the school blackboard or diary in the story: 000000009.
Nouns in Chinese homework composition topics or example sentences: meeting minutes of XX company in XX village, XX town and XX district. ...
Companionship: used to express the love relationship and passive situation between characters. For example, "Xiaoding× Xiao Na" means Xiaoding takes the initiative to attack and Xiao Na takes the passive defense. Please refer to the list of peer terms for details.
Because this symbol is inconvenient to input, it is generally replaced by the English letter "X" in daily communication. On HTML and XHTML, you can enter entity references ×, × or ×.
In an arithmetic book published by Stiefel in 1545, capital letters M and D stand for multiplication and division respectively. Steven also used this symbol in the book published by 1634, which means 3xyz2 now. Here Sec and ter represent the second and third unknowns, respectively.
David (159 1) regards AinB as the product of a and b, and some manuscripts and printed materials of15th century still use juxtaposition multiplication, such as 6x and 5x2. , but there must be letters, because 5 means 5+ instead of 5x, and this notation is still in use today.
The west calls "X" the cross of St. Andrew (because Andrew is one of the twelve disciples of Jesus, and is said to have been crucified), which has nothing to do with mathematics. /kloc-This number was used in some mathematics books published in the 6th century, but it was not used at the beginning of modern times. But two independent multiplication operations, such as 315172x174715 and 395903x295448.
The ancients in China and ancient Greece did not use the symbol of multiplication, but the latter used two numbers to represent multiplication (the same as addition). The arrangement and expression of numbers in the bamboo slips left in Bahr Shali, India; According to Unicode ISO 8859- 1, 2, 3, 4, 9, 13, 15 ISO 8859-8× U+00D7AA character code.