The objective of this study is to evaluate usability of the Vitamin 6th Grade Mathematics Module program interface. The program was made available to 12 students at a school with most frequently used 11-question task list and the results were recorded in an evaluation form. During the course of the test, participating students were asked to think loud. The tests were conducted one-on-one with each participant with 2 observers. In the evaluation phase, it was considered whether the test was completed or not. In addition, participating students’ behavior and statements were taken into consideration. At the end of the test, users found the program usable but they also made some suggestions.