本研究の目的は，前期初等教育における効果的な確率指導の方策について，第1学年の授業実践をもとに考察することである。そのために，まず，子どもの確率概念にかかわる誤認知をもとに，既存の単元の発展として確率領域と関連させた学習材を開発した。そしてその効果を，質問紙調査や記述整理によって分析した。 その結果，次の2点の方策を講じると，不確定な事象を論理的にとらえていこうとする力を育成することが示された。1点目は，学習材には身近な遊びの要素を取り入れ，試行実験を通して不確定な事象などへの気付きを深めていく場を設定することである。2点目は，グラフの特徴から数や式への着目を促し，身近な事象が具体的な数によって根拠づけられることの面白さを体感させることである。

The purpose of this research was to examine an effective teaching method of probability in the lower elementary education, based on the lesson practice to the first year students. First, the researcher developed a teaching material based on misunderstandings of the students, which were developed from an existing teaching material related to "probability". Second, the effects of the teaching material were analyzed by a questionnaire answered by the students. As a result, it became clear for students to be able to foster the ability to logically think an undetermined event when the following two points were taken into account. First point was that some daily game elements were introduced in the teaching materials and the students were given the situation to deepen their awareness to uncertain events by trials. Second point was to enable the students to focus on numbers and formulas from features of a graph and to give the students chances to experience of fun of awareness that some events in daily lives were demonstrated by numbers and formulas.