# Augmented Reality as a Didactic Resource for Teaching Mathematics
## 1 Introduction
Level 2 (augmented reality without marks): The markers that activate the information are replaced by the geolocation and user orientation given by the device's GPS or compass gyroscope. Thus, when the user is in a specific place on the Earth's surface, the digital information appears. Level 3 (augmented vision): Examples of this level would be Google Glass or Microsoft HoloLens glasses. This type of AR allows a totally personalized, immersive, and contextualized experience. In this case the information may arise due to the geolocation of the user or due to existing markers. Although it is not a new technology and despite being a great promise as a learning facilitator, its implementation in Spanish classrooms is rather discreet. The 2016 Horizon report [22] considered AR as an emerging technology that should be present in many classrooms in the academic year 2018-2019. According to [PERSON] and [PERSON] [23], the fact that AR is considered as a technology that improves learning, is based on two completely differentiated and independent theoretical frameworks:  
* The constructivist learning theories proposed by [PERSON] and [PERSON] affirm that people build their new knowledge based on what they already know and believe (this will depend on very different aspects such as their social and cultural backgrounds, the prevailing social context or previous personal experiences). According to these theories, AR has enormous potential to improve the construction of knowledge by students. * Situated learning theory states that meaningful learning takes place in a specific context, the quality of which depends directly on the interactions that occur between people, objects, places, processes, and culture ([PERSON], [PERSON] and [PERSON], 1989, cited by [23]). The use of AR produces a new mode of interaction for the student with the curricular contents, teachers, and other students, as well as with processes, places or culture, which would be beneficial for learning. The advantages of the implementation of this technology in classrooms are discussed in the literature [24; 25] and include the following:  
1. It would allow students to familiarize with new technologies and they would learn to handle them. 2. Education would be more interactive and didactic. 3. It would facilitate the development of cognitive, spatial, and motor skills. 4. It would increase the motivation and curiosity of students to learn, in addition to improving their creativity and imagination. 5. It would stimulate attention, concentration, short-term and long-term memory, and reasoning. 6. It would allow students to form critical attitudes of reflection to explain an observed phenomenon or the solution to a given problem. 7. It would facilitate understanding of the subject to be learned and encourage the autonomous learning of the student. For this, materials such as a textbook with AR tools could be developed. Disadvantages and problems of AR are also discussed in the literature [26] and include the following:  
1. It could be difficult to train teachers to be able to implement activities using this technology, although AR tools designed by other professionals could be used. 2. AR is difficult to implement in the classroom due to the high economic cost of computer equipment (mobile phones, tablets, or computers with quite powerful processors that allow the fluid use of this technology). 3. The general use of new technologies could deteriorate communication and relationships between people, making these relationships much more superfluous (humans communicate less face to face because they do so more and more through the new technologies). In education, this fact must be considered because it could cause students to interact less with teachers and other students, dehumanizing the teaching-learning process. 4. It could widen the digital divide between different population groups (especially among socially disadvantaged groups).