This research is aimed to know: (1) The kind of error students do<br />insloving The Material of Reading Exercise of Himpunan based on<br />Newman Procedure in class VII of SMP Swasta Al-Washliyah 8<br />Medan, (2) The causes of the students error insolving The Material<br />of Reading Exercise of Himpunan based on Newman Procedure in<br />class VII of SMP Swasta Al-Washliyah 8 Medan.This research is<br />qualitative research. The subject of the research is the students of<br />seven grade SMP Swasta Al-Washliyah 8 Medan Academic Year<br />2017/2018. The choice of this research subject is by taken 6 of 34<br />for students of VII-1 class, each consist of 2 higher level group, 2<br />medium level group, and 2 lower level group. This grouping is<br />based on the ranks of the student. Then, are chosen 2 studentswith<br />the lowest correct answer on each group. Data collection procedure<br />on this research use the method of the test and interviewing. Every<br />subject research was interviewed of their work result on Material<br />of Reading Exercises of Himpunan. Data analysis of this research<br />use Miles and Huberman Model consist of data reduction, data<br />presentation, and conclusion. The validity test of the data in this<br />study was carried out by Triangulation Technique.The results<br />showed that students made mistake in the type of Comprehension<br />Error, Transformation Error, and Process Skill Error. This error can<br />be seen from the following percentage: Comprehension Error<br />occurs as much as 14,71%, Transformation Error occurs as much<br />as 43,38% (this error is the most mistakes made by students), and<br />Process Skill occurs as much as 1,47%. The cause of the error is<br />not being able to change it into the symbol of Himpunan. They are<br />not used to write the questions, unable to plan a solution for the<br />problem, wrong in determining the right formula for the question<br />given, not realize their mistakes in the count of operations<br />performed, and can not count operations correctly.