Abstract The purpose of this study was to develop mathematical games to assist children in learning addition and subtraction computation. The investigator designed games and experimented through four extra lessons, then studied children¡¦s mathematical learning after the lessons. Participants of this study were second grade children from two elementary schools in Kaohsiung. The experimentation was divided into three phases: pilot phase, first edition phase, and, second edition phase. Data collection and administration included pre-test and post-test; questionnaire of children¡¦s attitude towards mathematics; questionnaire of children¡¦s attitude towards games; record sheets for loan of games; children¡¦s worksheets; learning diaries; researcher¡¦s observation notes; and, researcher¡¦s reflections on design of games. The researcher referred to the above data source, later, evaluated according to the results of experimentation, and completed final revisions. Data analyses and results were three: Design, implementation, and revision. Design. When designing a game, the materials followed that of children¡¦s real life experiences. The characteristics of the four games were: Cooperation, challenge, education, and, chance and luck. Implementation. Children changed from ¡§individual responsibility¡¨ to ¡§co-ordination and cooperation in group¡¨, from ¡§assurance¡¨ to ¡§lack of confidence¡¨, from ¡§marginal participation¡¨ to ¡§eager to play with laughter¡¨, and ¡§no control of shouting¡¨. From the data analyses, children performed well in cognition, attitude, and skills. Revision. The principles of modification were to evaluate games¡¦ strengths and weaknesses, and adjusting games design. The respective revisions were tutoring play, children as key persons, formulating regulations, and, enriching contents. The findings of this study suggested that children benefit from mathematical games and constitute mathematical learning in two-digit number computation. If instructors try hard to design games, be keen in administration, and adjusted games, children will learn through games and result more effective mathematics learning. Finally, it is concluded that the goal of enhancing mathematics learning through games-based instruction as feasible. Key word¡Gmathematics games, addition and subtraction computation

This diploma thesis deals with third-graders from one of Prague's elementary schools and their understanding of numbers. In addition to the Prodos textbooks, some didactical ideas were taken from the Fraus textbooks, which are aimed at the development of children's understanding mathematics. The experiments were carried out in a classroom and lasted one and a half year. Seven pupils were chosen to take part. The experiments were aimed at gauging their semantic and structural understanding of numbers. The pupils worked individually and were individually interviewed after the experiments. The assumption that pupils use strategies that are not taught in the classroom was confirmed, as well as the fact that the operation of subtraction is much more complicated than addition in mental arithmetic and also in written counting. However, the assumption that the pupils perform better when faced with financial matters as opposed to other situations was not confirmed. It came to light that when creating a verbal task, it is necessary to consider the pupil's understanding of the vocabulary used. Key Words: addition, subtraction, decomposition of number, computation, mathematics, calculative strategies