Discusses the importance of mental mathematics beyond the middle school. Presents sample objectives for different courses or strands, and teaching ideas to make mental mathematics an important, ongoing goal in secondary mathematics instruction and beyond. (KHR)

Describes an activity in which students observe a simple situation, explore conjectures, and generate conclusions from their exploration of the conjectures to develop the essential triangle-congruence theorems. Includes teacher's guide. (KHR)

A research focusing on the ability of the students to learn, the thinking capacity of the teachers and the languages, policy and technologies used in the classroom is conducted in order to understand and overcome the problem of students in learning algebra. The analysis shows that the problem is caused by the use of an instrumental approach…