# Collective problem-solving in Japanese primary mathematics lessons

## TL;DR

This paper explores how Japanese primary math lessons use a problem-solving approach through collective learning and structured teaching.

## Contribution

The study introduces three dimensions of Japanese math lessons and applies ATD to analyze their structure and dynamics.

## Key findings

- Japanese math lessons emphasize collective teaching and learning.
- The lessons are structured as a 'drama' with a clear chronological flow.
- The focus is on the evolution of mathematical knowledge through three geneses.

## Abstract

This study investigates the characteristics of Japanese primary school mathematics lessons that adopt a problem-solving approach. We argue that these characteristics are reflected in three key aspects: collective teaching and learning, the lesson as a “drama” (i.e., its structured flow), and the focus on mathematical knowledge. In this paper, we refer to these aspects as the collective dimension, chronological dimension, and epistemological dimension of Japanese mathematics lessons, respectively. Using the Anthropological Theory of the Didactic (ATD) as a theoretical framework, we analyze the mathematics lessons of a Japanese primary school, focusing on the evolution of milieus and the three geneses of mathematical knowledge (topogenesis, chronogenesis, and mesogenesis). Our aim is to highlight these dimensions and further identify the distinct features of Japanese lessons, as well as to demonstrate how, and to what extent, the evolution of milieus effectively captures the structure and dynamics of the Japanese lessons.