This study attempts to compare the topic "approximate value" in mathematics text-books of the 2nd year of South Korean junior high schools and that of the 3rd year of North Korean high schools. In addition, a survey questionnaire was distributed to junior and senior high school students as well as to mathematics teachers in South Korea. Based on the results of the survey, this study attempts to uncover the issues within the current teaching methods of "approximate value" and proposes the directions in which the teaching of approximate value should go in order to enhance mathematical thinking power and creativity of the students. First, it Is necessary to teach students how an error applies to the real world. To accomplish this end, it may be worthwhile to consider introducing the relative errors with more seriousness. Second, it is more important to teach the way of thinking which is concealed in the background of the calculation methods of approximate values than to simply teach mere calculation methods. Third, it is necessary to teach the calculation of approximate value with more realistic examples. Fourth, It is needed to teach students what the differences are when the terminology of "approximately" and "about" is used in real life and in mathematics.