Basic introduction Chinese name: equal sign mbth: symbol of equal sign: = explanation: meaning of equal sign Subject: Mathematical Pinyin: dě ng à o Basic content, source introduction, related expansion, teaching application, examples If the basic content, then A = B. Mathematical symbol: "=". Explanation: When one numerical value is equal to another, the equal sign "=" is used. For example: a=3, b=3, A and B are equal. That is, a=b (a equals b). "=" means that both sides are in the same position. For example, here the Y side is f(x), and f(x) is Y, and both sides are in the same position. Source Introduction In the mathematics books of 15 and 16 centuries, words were also used to express the equal relationship between the two quantities. For example, in some formulas at that time, the word aequ or aequaliter was often written, meaning "equal". 1557, British mathematician Colder said in his paper "The Grindstone of Wisdom": "In order to avoid boring repetition of the word isaequalleto (equal to), I have carefully compared many figures and symbols, and feel that there are no parallel equal-length line segments in the world with the same meaning." Therefore, Colder creatively uses two parallel and equal line segments "=" to represent "equality", and "=" is called equal sign. Replacing this word with "=" means equality, which is a progress in mathematics. Limited by the historical conditions at that time, the equal sign invented by Colder was not immediately adopted by everyone.
In history, others have used other symbols to express equality. For example, the mathematician Descartes used ∞ to mean "equality" in his book Geometry published in 1637. Until17th century, the German mathematician Leibniz strongly advocated the use of "=" in various occasions. Because of his great reputation in mathematics, the equal sign is gradually recognized by the world. Correlation expansion organically combines the two symbols "=" of ">" to get the symbol "≥". When one value is greater than another value or two numbers are equal, the greater than or equal sign "≥" is used, which is read as "greater than or equal to" and sometimes called "not less than". For any two real numbers A and B, their corresponding points A and B can be found on the same axis. If point A is to the right of point B or A and B coincide, then A ≥ B..
Similarly, when we understand ""and "<, we can simulate fairy tale scenes, such as" forest games ",and abstract the relationship between numbers from the comparison of different animals. The basic methods to compare the number of two kinds of objects are one-to-one correspondence and combination of numbers and shapes. Let students know their numbers through one-to-one arrangement, thus establishing the concept of "as much" On this basis, we can abstract "4 =4" through the combination of numbers and shapes, know and understand the meaning of "=", and let students know that when the number of two objects is "=". It can be seen that the cultivation of symbol consciousness needs solid experience as the foundation. In teaching, students should be encouraged to accumulate experience in the process of communication and sharing, learn various symbolic ways, and allow personalized expression of symbols. Gradually realize the superiority of symbolizing practical problems with numbers and shapes, and feel the value of symbols in the process of understanding and solving problems. Fill in "=" and ">" in the following () as examples. 、“& lt。 A)12 ()13-1b) 4 * 4 () 5 * 30c)10 () 9 *1+1Answer: a) "= b)" & lt； ; c)= .