Abstract-This research aims to develop mathematics learning materials based on multiple intelligence theory and learning trajectory with conceptual knowledge oriented in the topic of probability for Junior High School's students grade VIII, which are valid, practical, and effective. The learning materials includes Lesson Plan and Worksheet that provide various facilities to students, for example through variations of learning activities, contexts, and illustrations, and by emphasizing on the hypothesis of students' thinking and teachers' alternatives responses so that the teachers can handling the difficulties which students face during the learning process. Type of the research was research and development with ADDIE model, consisting of Analysis, Design, Development, Implementation, and Evaluation. The lessons plan was valid with a score of 3.99 on a scale 5. While the worksheet obtained a score 4.09 on a scale 5 with valid category. Based on practicality evaluation result of student's questionnaire, learning materials obtained a score 3.47 on a scale 5 with practical category and observation sheet of learning implementation percentage was 86.84%. Then, there are 86.11% students who have a minimum understanding of the concept in the high category. Based on z-test, the learning materials are effective with level of significant 0.05.

No abstract

Probability is one part of mathematics material that is learned in school. In Indonesia, probability is learned from Junior High School level and is continued in Senior High School level. Hence, understanding of probability's concept in Junior High School level is very important. The aim of this research is to analyze students' difficulties of 8 th Grade of SMPN 1 Prambanan Klaten in solving problems of probability. The method used in this research is descriptive method. Data collection was done based on students' work through essay test. The result shows that the difficulties which are experienced by the students in solving pobability's problem are the difficulty in understanding proportional reasoning and the difficulty in resolving misconceptions or misperceptions in probability. The misconceptions are representativeness, probability cannot be measured mathematically, misuse or extend conclusions inappropriately, inappropriate reasons, beliefs, equi-probability bias, and possible means certain.