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…

A good-quality teacher may determines a good-quality learning, thus good-quality students will be the results. In order to have a good-quality learning, a lot of strategies and methods can be adopted. The objective of this research is to improve students' ability in determining the rules of a numeric sequence and analysing the effectiveness of the…

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 about decimals is an important part in mathematics. However at the same time, decimals are known as the abstract numbers for students. Mostly in Indonesia, decimal is taught only as another notation for fractions or percentages. There are no meaningful references for them such as the use of concrete situations. This study aimed at…