学英语

<正>There is a passage about negative numbers.Negative numbers are a necessary part of our understanding of mathematics and the world.The idea of anything"negative"is often seen as"bad".Negative numbers are not only good,but also fun!Today you will learn more about negative number.     

Components of Place Value Understanding: Targeting Mathematical Difficulties When Providing Interventions

Place value understanding requires the same activity that students use when developing fractional and algebraic reasoning, making this understanding foundational to mathematics learning. However, many students engage successfully in mathematics classrooms without having a conceptual understanding of place value, preventing them from accessing mathematics that is more sophisticated later. The purpose of this exploratory study is to investigate how upper elementary students' unit coordination related to difficulties they experience when engaging in place value tasks. Understanding place value requires that students coordinate units recursively to construct multi‐digit numbers from their single‐digit number understandings through forms of unit development and strategic counting. Findings suggest that students identified as low‐achieving were capable of only one or two levels of unit coordination. Furthermore, these students relied on inaccurate procedures to solve problems with millennial numbers. These findings indicate that upper elementary students identified as low‐achieving are not to yet able to (de)compose numbers effectively, regroup tens and hundreds when operating on numbers, and transition between millennial numbers. Implications of this study suggest that curricula designers and statewide standards should adopt nuances in unit coordination when developing tasks that promote or assess students' place value understanding.     

Prime Factors

<正>In mathematics,every positive integer has a single unique prime factorization.The process of determining these factors is called integer factorization.Today we will talk about"Prime Factors".Find the prime factorization of a composite number,and find the way to integer factorization.When two or more numbers are multiplied,each number is called a factor of the product.     

Peano's concept of number

Giuseppe Peano's development of the real number system from his postulates for the natural numbers and some of his views on definitions in mathematics are presented in order to clarify his concept of number. They show that his use of the axiomatic method was intended to make mathematical theory clearer, more precise, and easier to learn. They further reveal some of his reasons for not accepting the contemporary “philosophies” of logicism and formalism, thus showing that he never tried to found mathematics on anything beyond our experience of the material world.     

基于联系数贴近度的区间数多属性决策方法

利用集对分析和联系数学理论对区间数多属性决策方法进行了研究.首先给出了联系数贴近度的定义和性质;然后在将区间数决策矩阵转化为联系数决策矩阵的基础上,依据传统的逼近理想解的排序方法(TOPSIS)的基本思路,基于联系数贴近度提出了一种区间数多属性决策新方法.该方法简洁直观,易于计算,无需对区间数进行排序;最后,通过算例表明了它的有效性和实用性.     

About one - an inquiry about the meanings and uses of the number one

The story of the number one is told. The long struggle to recognize one as a number is described. The role of the number one in philosophy, religion, mathematics and science is briefly discussed. Finally, the relationship between one and some other numbers is presented.     

The effect of quantitative reasoning on prospective mathematics teachers’ proof comprehension: The case of real numbers

We report a mixed-methods research study investigating the effect of quantitative reasoning on prospective mathematics teachers’ comprehension of a proof on real numbers. Nineteen prospective mathematics teachers engaged in quantitative reasoning while developing real numbers as rational number sequences in a series of instructional activities. All participants completed a proof comprehension assessment prior to and upon completion of the instruction. Six of the prospective mathematics teachers also participated in semi-structured interviews after the post-test. Results showed a significant difference in proof comprehension performance between the pre- and post-tests. Moreover, results from the interviews showed that prospective teachers reasoned quantitatively on the proof comprehension dimensions. Results suggest that engaging in quantitative reasoning during instruction may help to develop proof comprehension, particularly in situations involving the analysis of proofs entailing properties of the real number system. We recommend embedding quantitative reasoning in teacher education and professional development programs to facilitate mathematics teachers’ proof comprehension and proving activities.     

The possibilistic moments of fuzzy numbers and their applications

This paper, introduces the nearest weighted interval and point approximations of a fuzzy number, and then suggests weighted possibilistic moments about these points of fuzzy numbers. The possibilistic moments play an important role in fuzzy sets and systems, specifically in physics, mathematics and statistics. We provide the definition of the moments of fuzzy numbers as well as the definition of moments in probability theory; some of their applications are mentioned.     

Novel methods on comparing grey numbers

Uncertain decision-making is an important branch of decision-making theory. It is crucial to describe uncertain information, which determine the decision-making is effective or not. This paper first presents a brief survey of the existing methods on denoting uncertain information, such as fuzzy mathematics, stochastic and interval methods, analyzes the merits and demerits of these methods. Then the paper proposes a novel method grey systems theory to describe uncertain information and gives the novel definition of grey number on the basis of probability distribution. Subsequently a novel probability method on comparing grey numbers, especially discrete grey numbers and interval grey numbers, is studied. When an interval grey number satisfied to continuous uniform distribution, it will be degenerated into an interval number. Finally three numerical examples are investigated to demonstrate the effectiveness of the present method.     

学英语(英文)

<正>In mathematics,Algebra is a language of symbols.One symbol that is often used is a variable.A variable is a symbol,usually a letter,used to represent a number.Algebraic expressions are combinations of variables,numbers,and at least one operation.Today we will talk about"Algebra:Variables and Expressions".     

Children's strategy use and interpretations of mathematical representations

This is a summary of research, from an information processing perspective, of children's interpretation and use of strategies and representations for place value, subtraction and addition in the first three years of school. Representations are defined broadly to include concrete embodiments of numbers, symbols for numbers and operations, and combinations of the latter in number sentences and algorithms. The objective was to assess the value and limitations of the use of representations in early mathematics learning and teaching and hence to identify, describe and examine critically some of the strategies and representations that children and teachers use in early mathematics. Children generally chose to use verbal and mental strategies in preference to formal algorithms, and did not want to use analogs unless they could not perform the task in any other way. The latter preference is explained on the basis of the extra demand that use of analogs adds to the cognitive process unless they are used automatically.     

Visual representations as objects of analysis: the number line as an example

Our paper examines the representational nature of number lines as they are used in instructional tasks. The examination is informed by a so-called mathedidactical analysis of the number line as a tool used in teaching students mathematics. This analysis led to the identification of a family of number line models, based on visual aspects of number lines each reflecting different forms and functions. In the article, number line tasks are unpacked to illustrate the visual representational components of particular number line models. We illuminate how these components of the models provide tools to locate whole numbers and integers, operate with them, and facilitate reasoning and understanding of underlying mathematical concepts.     

模糊量及模糊数的表现特性

模糊集的表现定理是模糊数学的最基本理论.在表现定理的基础上,对各种模糊量:包括凸模糊量、正规模糊量、正规凸模糊量、凸有界模糊量、模糊数、有限模糊数、对称模糊数的表现定理进行了深入的研究,从而建立了不同类型模糊量与普通集合之间的联系.     

Increasing Equity and Achievement in Fifth Grade Mathematics: The Contribution of Content Exposure

This study uses a large nationally representative data set (ECLS‐K) of 5,181 students to examine the extent to which exposure to content and instructional practice contributes to mathematics achievement in fifth grade. Using hierarchical linear modeling, results suggest that more exposure to content beyond numbers and operations (i.e., geometry, algebra, measurement, and data analysis) contribute to student mathematics achievement, but there is no main effect for increased exposure on developing numbers and operations. Two significant interactions between exposure to specific content and racial composition of the classroom emerge. Specifically, as exposure to more diverse content increases, the classroom mathematics achievement gap among students in predominately Caucasian classrooms and those composed predominately of students of color appears to narrow. Findings are discussed with regard to promoting increased opportunities to learn mathematics for students in racially diverse classrooms.     

基于Bonissone近似算法的群决策方法

把模糊数学理论应用到群决策领域是解决不确定问题的有效方法 .介绍了定性语言描述转化成定量模糊序关系的方法 ;采用 Bonissone的 L-R梯形模糊数近似算法 ,提出了基数型和序数型决策问题的群决策程序 ;用实例说明了这种群决策方法的使用步骤 .     

Functions and Shapes in the Light of the International System of Units

Famously, Galilei made the ontological claim that the book of nature is written in the language of mathematics. Probably, if only implicitly, most contemporary natural scientists share his view. This paper, in contradistinction, argues that nature is only partly written in the language of mathematics; partly, it is written in the language of functions and partly in a very simple purely qualitative language, too. During the argumentation, three more specific but in themselves interesting theses are put forward: first (in Section 3), there are more shapes than real numbers; second (in Section 4), the metrological notion ‘amount of substance’ can profitably be exchanged for ‘number of entities’; third (in Section 5), prototypical concepts will always be scientifically important.     

Pre-service mathematics teachers’ concept images of radian

This study investigates pre-service mathematics teachers’ concept images of radian and possible sources of such images. A multiple-case study was conducted for this study. Forty-two pre-service mathematics teachers completed a questionnaire, which aims to assess their understanding of radian. Six of them were selected for individual interviews on the basis of theoretical sampling. The data indicated that participants’ concept images of radian were dominated by their concept images of degree. As the data in this study suggested, pre-service mathematics teachers were reluctant to accept trigonometric functions with the inputs of real numbers but rather they use value in degrees. More interestingly, they have two distinct images of π : π as an angle in radian and π as an irrational number.     

学英语（英文）

<正>In mathematics,the median is the middle value in the list of numbers.The mode is the value that occurs most often.If no number is repeated,then there is no mode for the list.Today we will talk about"Median and Mode".Median and Mode     

论自然数列的二重性与双相无限性及其对数学发展的影响

自然数列的潜无限观与实无限观是众所周知的。正是两种无限观的对立,形成了近代数学史上直觉主义派与公理主义派及逻辑主义派在数学基础问题上的根本分歧及对重建基础的不同主张。本文旨在揭示出自然数列的二重性,即内蕴性和排序性的关系;从而引出“双相无限性”概念,由此也就澄清了诸流派在无限观上形成分歧的根本原因。这对教学和数学史研究都有相当意义。本文主要内容曾于1994年11月上旬在南开数学研究所举行的“首届数学哲学与方法论研讨会”上报告过。