This study aimed to develop and evaluate an instructional material which is a General Mathematics Workbook for the Grade II students in the Senior High School. The study used developmental research design to describe the processes involved in performing the instructional design, development and evaluation activities. The workbook was evaluated by the experts and teachers in Mathematics, who were chosen purposively, considering the following criteria: content, format, presentation and organization and accuracy and up-to-datedness of information. The results of the evaluation showed that the comprehension questions written on the workbook meet the cognitive demand required, the components of the material are appropriate for the intended use, features of the workbook are presented well, and it can capture the attention and interest of learners and the presentation of the content will not lead to the development of misconceptions or misunderstandings since there are no misspelled words and outdated information found. In summary, the ratings obtained in the different criteria gave an impression that the workbook was recommended for school use. However, to extend its use in other public Senior High Schools, validation of its effectiveness to the Grade II students and evaluation by more experts and teachers is highly advised.