Abstract
The study aimed to develop and validate a test for the measurement of mathematical thinking of secondary-level students. The first-stage aspects of mathematical thinking were explored for a consolidated model in line with the curriculum of secondary-level education in Pakistan. Thirty-six items were developed and piloted in three schools. Factor analysis was applied to ensure the construct validity of the instrument. The analysis shows that each item was significantly loaded in its corresponding construct with a little deviation shown by two of the 36 items. The data show that this deviation was caused by the overlapping nature of the content and construct.