Mathematics teachers face great difficulties during virtual communication with their students, mainly because scientific and technical subjects use a great many mathematical symbols, abstract objects and a wide variety of technical nomenclatures that are not directly represented on the keyboards of computers, tablets or other communication devices. This paper aims to facilitate oral and written communication between teachers and students in mathematics subjects. In this regard, we describe realistic procedures for use in virtual office hours. We analyse different methods that combine the use of computers, tablets, webcams and an institutional video lecture system. The improvement in oral and written communication will have a positive effect on academic performance and decrease the dropout rate in distance learning courses, because the students feel more closely accompanied in their learning.