Learning through social media platforms is a nascent pedagogy that opens up new virtual online e-instructional modalities and avenues to be explored especially in these challenging emergency times of COVID-19. This research focuses on a self-directed initiative of a math teacher who taught her students in an open virtual class via Instagram. This study explores how the main features of Instagram -inherently used as social interaction platform - were maximized for educational purposes. It also investigates the effects, be they positive or negative, on the learning-teaching process in terms of engagement and communication. For this, a mixed-method sequential exploratory design was opted for to conduct the study which surveyed 100 students across 22 different high schools who took part in the virtual open math classes. The findings highlight the different patterns of Instagram use and platform features that lend this social media website the requisite feasibility to educationalize it. Furthermore, the results reveal both the favourable and disadvantageous aspects of Instagram.