定义是数学教学的重要基础,逻辑推理、运算的依据,判断的前提,新旧知识的纽带。数学中的概念通常以定义的形式出现,下定义必须遵守下述的规则:定义应该是相称的;定义不应当是循环的;定义不应是否定的;定义应当是简明清晰的,不应当用譬喻的说法。下一个定义,特别应注意它的含义和适用的范围,即注意被定义的概念的内涵和外延,定义不能含混不清和模棱两可,定义要做到无懈可击,在实践中经得起检验和推敲,要能充分体现它的真实性、可靠性和科学性。为此通用小学数学教材第九册中有关繁分数的定义就 Definition is an important foundation of mathematical teaching, logical reasoning, computing basis, the premise of judgment, the bond between old and new knowledge. The concepts in mathematics often come in the form of definitions, the following rules must be followed: definitions should be proportionate; definitions should not be cyclic; definitions should not be negative; definitions should be concise and clear and should not be used For example. The next definition, with particular attention to its meaning and scope of application, that attention should be defined connotation and denotation, the definition can not be ambiguous and ambiguous, the definition to be impeccable, in practice, stand the test and scrutiny, to Can fully reflect its authenticity, reliability and scientific. To this end universal primary school mathematics textbook ninth volume definition of the number