Abstract
This study reports on the development of an instrument to measure fraction division operation sense. Internal content validity of the instrument was established following an extensive item creation and pilot testing. The instrument thereafter was administered to 113 pre-service teachers with an aim to evaluate its internal consistency reliability. Cronbach's alpha for the total score of instrument was .888. To evaluate test-retest reliability, 59 out of the 113 pre-service teachers used the instrument twice, 14 days apart. Pearson's correlation for the total score of instrument was .929. These results provide favorable evidence for the reliability of the instrument.