乗法九九学習を成功させるためには,児童の心身の発達および経験内容から考察して,何才何か月ごろから開始するのが,最も適当であるかを研究すること。さらに,算数学習のレディネスに影響を与える要因についての分析的研究をすることの2つを目的とした。実験方法は,アメリカの「算数の学年配当7人委員会」の方法を改善し,4つの実験群を設けた。この各実験群に,第1基礎テスト,第2基礎テスト,予備テスト,終末テスト,把持テスト,知能検査,配慮実験,ゲス・フー・チストその他の調査を実施した。被験者は,大,中都市,農村の8小学校2年,3年生1,046名を対象に22名の教師が,同一指導案によって指導した。本実験の基準に従って整理した結果では,乗法九九学習の指導開始は,8才1か月(2年2学期)から行なっても可能であることが実証された。現在,8才7か月(3年1学期)から開始しているが,さらに,6か月早めても,わが園児童の場合は,可能であると考られる。これは,アメリカのC.Washburneらの実験に比べ,2才1か月早い。また,算数学習のレディネスの要因としては,(1)算数学習に必要な知能,(2)四反応の速さ,(3)視聴覚および視聴覚器官の障害の有無,(4)健康,栄養,疲労の条件,(5)家庭的背景,(6)情緒の安定性,(7)根気の強さ,(8)自主性,(9)数の視聴覚記憶,(10)語の視聴覚記憶,(11)算数に対する興味,(12)算数的経験などが重要なものであることが実証された。

In this study, the readiness for the study of arithmetics, especially for the multiplication facts is investigated. There is a great difference between the effect of teaching before a child become mentally ready for the arithmetic and the effect of teaching after the readiness is nearly achieved. Therefore, curriculum should be made along with the psycho-10gical growth of children. Children , may not be willing to meet each unit in the course of study unless they are not mentally ready for it. 1) Purpose : This study has two purposes : the first is to decide the most adequate time for the study of the multiplication facts in accordance with the physical and psychological growth. The second is to analyse the factors related to the arithmetic readiness. 2) Method : The method of this study consists of comparative experiments and the subjects are the second and third grade children of eight elementary schools in Tokyo City and in Gifu Prefecture. A thousand and forty-six subjects in total were divided into four homogeneous groups in respect to intelligence and knowledge in primary arithmetics. Only ,difference among them is the time of beginning of the experiments. Group I began from the second term of the second grade (September), group III from the third. term of the second grade (January), Group III:, from the first term of the third grade (April), and Group VI, from the first term of the third grade (June). These group were taught by the same method, on the same materials by 22 teachers for each group. Then the First Foundation Test, The Second Foundation Test, Pretest, Final Test and Retention Test were given in the following order. (Fig. I ) In order to analyse other factors which may give effect to arithmetical readiness, the investigator Research administered the New Tanaka Intelligence Test B, Guess-Who-Test. Self-Diagnosis-Test. Preference-Test. Memory-Abilities -Test, Home -Environment- ' Test and so forth. To establish a criterion for adequate mastery of the multiplication facts learning, the standard of the Committee of Seven on Grade Placement of Arithmetic topics in U. S. A., was adopted. The standard is "Adequate mastery means the degree of mastery which enables more than 80% of children to pass the retention test which is administered after six weeks. " 3) Results : Mental age for the multiplication facts learning which enables three-fourths of the children to reach 80 percent mastery is found to be eight years and one months (the 2nd term of the 2hd ' grade). This age is considered as the most adequate level at which teaching of multiplication facts can be begun. It is recommended, therefore, Japanese children can be taught six months earlier than as they are with the present curriculum. The factors which are' relevant to the arithmetic readiness are as follow : 1) The intelligence to be needed for arithmetic learning.