**2. Related works**

Stimulating multiple sensory dimensions during the learning process of a concept or idea makes the learning itself more effective, because our mind needs to experience the reality all around by multiple experiential levels. Indeed, it is essential for us to look, listen and touch in order to build a complex conceptual structure that bears and strengthens our knowledge about reality itself [22, 23]. This multisensorial learning is also important in special-need situations, such as autism [24, 25] or dyslexia [26, 27].

Compared to traditional two-dimensional learning systems, such as a book or the simple screen of a PC or tablet, an immersive study environment has several advantages, as it gives the spatial understanding of the concepts exposed, more peripheral awareness or more useful information bandwidth and decreasing the information dispersion phenomenon [28].

The natural sciences have pioneered the use of Virtual Reality techniques to facilitate the learning of their subjects: chemistry [29–33], biology [34], physiology [35], physics [36].

An effective approach to enhance math skills, knowledge and competences inevitably involves the creation of dynamic digital environments rich in captivating content, which would even reduce anxiety and improve results [37].

Mathematics is known to be one of the most difficult subjects for many students. A recent study asks questions about traditional way of learning and recommends more active and attractive learning approaches [38].

Furthermore, many several studies have shown that immersion in a digital environment can significantly improve education in several ways, because, as mentioned earlier, multiple perspectives are activated at the same time [39]; this fact has an important impact in all areas of mathematics [40].

In some works it has been pointed out that many students find very difficult to relate a function's analytical form to its relative graph, despite the mathematical simplicity of the concept of the function itself [41]; it almost seems that the intermediate layers existing between the set concept and the analytic-geometric one prevent a clear understanding of the link [42, 43].

A recent study has shown that a deeper understanding of the analyticalgeometric links existing in functions, if supported by specific software, can help students to develop a positive mindset towards mathematics itself, in terms of attitude, motivation, interest and competence [44]. But we assume for what is the current state of the art that more research is needed to grasp the profound implications that exist.
