“REINVENTING” TECHNIQUES FOR THE ESTIMATION OF THE AREA OF IRREGULAR PLANE FIGURES: FROM THE EIGHTEENTH CENTURY TO THE MODERN … (original) (raw)

Problem-solving activity ancillary to the concept of area

This paper concerns the results of the second stage of a two tier program designed to enhance students' technique usage in area measurement. The first stage involves 11 year old students; certain techniques were didactically introduced with the dual purpose of cementing the concept of area and area preservation, and of giving the students tools for explicit area measurement (either exact or estimates). The second stage deals with the development of the same techniques, but the focus is not now primarily on the direct enhancement of the central concept (area) but on the reassessing, re-examining and adapting of the techniques themselves. The paper reports on a case study concerning two 13-year old students' output analyzed from this latter context. Their work in particular shows several ways that they could refine the 'technique' of decomposition of plane figures.

Reflections and knowledge of teachers who study the area of plane figures

2020

This study aims to discuss and understand the process of (re)significance of teachers’ professional knowledge based on discussions and reflections carried out by a group of teachers who teach mathematics for the initial years of the elementary education. The teachers studied how to calculate the area of plane figures using squared arrays. This study is based on Zeichner’s and Serrazina’s research to discuss the reflection on the practice and, in Ball, Thames, and Phelps, to analyse the (re) significance of the knowledge of the professionals involved. The data analysed were collected during the group meetings at the school where the participants taught. Through the analyses of the discussions held, we could observe that the teachers expanded their common and specialised content knowledge, mainly in relation to the strategies to calculate area, and started using reconfiguration of the figures and formulas of area more assertively. Mutual support allowed them to identify their own need...

The level of understanding geometric measurement

2015

The perimeter and area are two important geometric concepts, which are taught through many years in schools. Although the curriculum and the textbooks in Hungary consist of both qualitative and quantitative approaches by teaching area and perimeter, the students' performance is low. The main goal of this research is to investigate students' ideas of the concepts area and perimeter from 5 th to 8 th grade. We identify typical solving strategies in order to understand students' imagination connected to these mathematical objects.

Complex and Non-Regular Shapes: Their Evolution in Greek Textbooks (1749–1971)

Science & Education, 2008

Current research suggests that problem solving concerning complex and non-regular shapes can enhance the acquisition of the concept of area. Despite the fact that this topic was always present in Greek mathematical textbooks it disappeared in the modern ones. In this paper we deal with the way the specific topic has been presented for a long period (since 1749 until 1971). We describe the methods that known Greek scholars proposed for the calculation of the area of complex and non-regular shapes and how the content of the relevant problems varies through these three centuries according to the social circumstances that affected the philosophy of the educational system.

Developing problem-solving strategies via estimating the area of irregular shapes

… though mathematical education. Proceedings of the …, 2008

In this paper we are interested in the work of 6 th graders (11-12 years old) when they face non-standard tasks with the area of irregular shapes. These shapes add to the students an extra level of difficulty when they include curved lines in their boundaries. We record the strategies the students decided to apply in order to overcome these difficulties. We further analyze their work for whether there is evidence the strategies are primarily due to the computer environment or the use of paper and pencil.

Kordaki, M. & Balomenou, A. (2006). Challenging students to view the concept of area in triangles in a broader context: exploiting the tools of Cabri II. Ιnternational Jοurnal of Computers for Mathematical Learning pp. 1-36. (Editor: Saymour Papert). (SJR: 0.186, If (SNIP): 0.815).

This study focuses on the constructions in terms of area and perimeter in equivalent triangles developed by students aged 12 to 15 years-old, using the tools provided by Cabri-Geometry II (Laborde, 1990). Twenty-five students participated in a learning experiment where they were asked to construct: a) pairs of equivalent triangles ‘in as many ways as possible’ and to study their area and their perimeter using any of the tools provided and b) ‘any possible sequence of modifications of an original triangle into other equivalent ones’. As regards the concept of area and in contrast to a paper and pencil environment, Cabri provided students with different and potential opportunities in terms of: a) means of construction, b) control, c) variety of representations and d) linking representations, by exploiting its capability for continuous modifications. By exploiting these opportunities in the context of the given open tasks, students were helped by the tools provided to develop a broader view of the concept of area than the typical view they would construct in a typical paper and pencil environment.

CALCULATION OF AREAS : The discussion of a mathematical-historical problem that exposes students ’ conceptions of Proofs

The present study constitutes an attempt to check students' conceptions about the nature and the significance of mathematical proofs. The setting of this study was a mathematical-historical discussion within the framework of a course dealing with the development of mathematics. The students-elementary school pre-service mathematics teachers-were exposed to some problems taken from the Egyptian mathematics. After the lesson – that included the presentation of a formal proof of the main statement discussed-the students were asked to answer individually and in writing questions concerning the Egyptian method to calculate the area of a quadrilateral. The analysis of their answers reinforces the conception that pre-service teachers may know how to perform the " ceremony " of proof but in general, they do not appropriately conceive its meaning or its role establishing truth in mathematics.

Tasks Involving Perimeter and Area of Plane Figures: Analysis of a Mathematical Textbook

2017

The aim of this study is to know what a mathematics teacher can do in the class to vary the type of language used in the textbook. The methodology was qualitative (case study). Data were collected from the written registers of a group of students with four elements (aged 11-13), the teacher’s notes and the textbook used in their school. We characterized the 84 tasks (total of 96 questions) presented in their textbook related to the notions of perimeter and area of plane figures in middle school (6 grade). The results showed that the questions of the tasks had a statement which involved verbal and visual language types (62/96); a statement with verbal language (25/96), a statement with three types of languages (8/96) and a statement with verbal and symbolic language (1/96). We found 81 transformations limited to the same language: symbolic language (53/81), visual (22/81) and verbal (6/81). Transformations which involved two language types were found as following: (i) from visual to ...

YOUNG PUPILS’ INTUITIVE UNDERSTANDING AND STRATEGIES OF AREA MEASUREMENT

The 28th International Scientific Conference “Educational Research and School Practice”, BOOK OF PROCEEDINGS "THE STATE PROBLEMS NEEDS MODERN EDUCATION COMMUNITY", Editors Jelena STEVANOVIĆ Dragana GUNDOGAN Branislav RANĐELOVIĆ, 2022

Learning area measurement in mathematics instruction implies certain phases that entail rhetorical and symbolical generalizations in terms of mathematical formulas (Smith III & Barrett, 2017; Zacharos, 2006; Zeljić & Ivančević, 2019). It is through mathematical formulas that geometry is represented in Serbian mathematics curricula and this fact is the starting point of our research. When pupils have to solve mathematical tasks, they use various strategies that differ in terms of the correctness of their solution, the time needed for completing the task, and task requirements and scope (Siegler, 1991). To measure the area of a rectangular and overcome the problems arising from pupils’ misunderstanding of the area formula, it is recommended to take a closer look at the structure of the rectangular array by covering the area of the rectangular with a mathematical manipulative in the form of a unit of measurement that pupils are intuitively familiar with from the onset (Đokić, 2014, 2017; Van de Walle, Karp & Bay-Williams, 2013). The concept of covering would enable pupils to conceptualize the relationship between the unit’s dimensions and the dimensions of the rectangular. After this phase, through length measurement and multiplication, pupils can solve the area measurement task using mathematical formulas with understanding. Apart from the covering strategy, the paper looks at the ways pupils conceptualize area (Outhred & Mitchelmore, 2000; Reynolds & Wheatley, 1996; Nunes, Light & Mason, 1993). Can an actual misunderstanding of the structure of a rectangular array be found in our mathematics curricula and, if so, can it be overcome by applying the idea of covering the area of a rectangular array? We conducted an empirical study on pupils’ strategic approaches to covering the area of a rectangular in order to understand how pupils calculate its area. We identified the strategies used by pupils and examined their stages of development.

ASSESSING THE AREA OF BASIC GEOMETRICAL SHAPES AND PROVING SIMPLE IDENTITIES, VIA EUCLIDIAN TRANSFORMATIONS, WITHIN DYNAMIC GEOMETRY SYSTEMS

Initially, this work deals with the fundamentally significant concept of geometric transformation which is responsible for the classification of Geometries. Afterwards, the Euclidean transformations such as translation, axial symmetry and rotation are presented as special cases of isometries, since they conserve the distances and the measures of angles. Data research, contrary to the cognitive regards, shows that medium school age students are confused in the implementation of such transformations. This study proposes that Euclidean transformations can be comprehended, via the exploitation of the tools of Dynamic Geometry System of Cabri Geometry II. Then these transformations are considered as cognitive vehicles so that they may become helpers in assessing the area of basic shapes of plane geometry such as parallelograms, triangles, trapeziums, circles and polygons and proving simple identities through the method of splitting parts of an object and recomposing them. Finally, anticipating the benefits of consolidation, the Haberdasher's Puzzle is proven by cutting an equilateral triangle into four pieces that may be rearranged in order to form a square through Euclidean transformations.