This study aimed to identify the percentage of the value-added measures in the performance of Mathematics teachers in North Al Batinah Governorate schools in the Sultanate of Oman. It also aimed to investigate the influence of experience, gender and Willaya variables on the value added percentages. Moreover, the study suggested some procedures to develop teachers' performance according to the value added measures. To achieve these aims, the researcher adopted the descriptive approach. The population of the study involved all grade ten math teachers in the public schools in the North Al Batinah Governate which included (161) teachers, (83 Males and 78 females), and all grade ten students which included (9771) students in North Al Batinah Governorate. The data was analyzed using (SPSS). Means, standard deviation and analysis of variance (ANCOVA) were also used in the analysis. The findings of the study revealed that there was value added in students' performance which had a percentage of 7.58% for the teachers in the sample, considering students average results in grades nine and ten which was (45.77%, 53.35%) in order. These results showed moderate performance which tended to be low in regard to the average scores. In addition, it was found that there were statistically significant differences with respect to gender and Willayat variables. It also revealed that there was no statistically significant differences related to experience. Based on the previous findings, the study recommended spreading the value added culture in schools and establishing regulations and legislation that could help in implementing value added measures in performance evaluation. It also recommended activating the monitoring