Abstract
The purpose of this paper is to evaluate the mathematics education in right after the end of World War II as a phase of continuous process from the pre war period to post war period. In the prior literatures of history of mathematics education, the period was placed as an age of discontinuity between pre and post war. However focusing on the instruction of multiplication and division by fraction, there were aspects of continuation for instructional improvement. From such a point, we review the improvement in pre war period and identify the continuation of the instructional improvement in the period.
As a result, the changing from teaching the method of calculation to helping students to understand the meaning of calculation were pointed out as an instructional improvement in pre war. The point can be seen in right after war period, then it continued to post war period. And in post war period, the meaning of multiplication and division by fraction were explained with the proportional relationship of numbers. Then multiplication is the calculation to find the quantity expressed by proportion, and division is the calculation to find the proportion and base quantity. Such an explanation was organized in right after war period and became the foundation of instructional explaining in post war. From the point, the instructional improvement in pre war continued in right after war period and post war period.
