Students encounter difficulties in solving areas of triangles and quadrilaterals due to a lack of conceptual understanding of the topic. The researchers have developed the following activities and the hypothetical learning trajectory (HLT) through the design research approach focusing on developing activities for students to learn the concepts…

Learning Transformation Geometry (TG) needs a more informal approach to concern situational problems. This study aims to develop actionable knowledge of TG in the form of design related to context and yet general enough to use digital manipulative activities in new situations. We propose such knowledge in the form of conjectured Local…

There are various misconceptions students have when studied quadrilateral which encourages efforts needed to overcome these misconceptions. This study aims at overcoming misconceptions by designing learning trajectories in the topic of Quadrilateral applying the Realistic Mathematics Education (RME). Design research carried out at one of junior…

Lines and angles are essential for students because of geometry and its many applications in daily life. However, there are still many students who have difficulty grasping the material. Therefore, it is necessary to design learning using the right approach, context, and media. This study aims to produce a learning trajectory that can assist…

Semiotics is simply defined as the sign-using to represent a mathematical concept in a problem-solving. Semiotic reasoning of constructing concept is a process of drawing a conclusion based on object, representamen (sign), and interpretant. This paper aims to describe the phases of semiotic reasoning of elementary students in constructing the…

The use of concrete objects in a real-life situation is one of the effective ways for teachers to teach and students to explore and learn transformation geometry. The present study, which used a local wisdom or learning context (called Malay woven motif of Kepulauan Riau), focused on developing the reasoning of transformation geometry with…

Many researchers found that students have difficulties in understanding area measurement. Students mostly focus on applying formula to find the area of certain shapes without knowing what the area is and why the formula works. It is important for the students to know what attribute being measured and to construct the unit for area measurement.…

This paper reports a study on designing and testing an instructional sequence for the teaching and learning of the concept of angle in Indonesian primary schools. The study's context is employing the current reform movement adopting "Pendidikan Matematika Realistik Indonesia" (an Indonesian version of Realistic Mathematics Education).…

Usually, multiplication is introduced to students to represent quantities that come in groups. However there is also rectangular array model which is also related to multiplication. Barmby et al. (2009) has shown that the rectangular model such as array representations encourage students to develop their thinking about multiplication as a binary…

Learning the concept of perimeter and area is not easy for students in grade 3 of primary school. A common mistake is that students think that if the area is the same, the perimeter also has to be the same. It is difficult for them to understand that for a given area, there are many possibilities of perimeter and vice versa. When student are not…

The first volume of the 29th annual conference of the International Group for the Psychology of Mathematics Education contains plenary lecture and research forum papers as listed below. Short oral communications papers, poster presentations, brief summaries of discussion groups, and working sessions are also included in the volume. The plenary…