Research Article https://doi.org/10.12973/eu-jer.11.4.2031 European Journal of Educational Research Volume 11, Issue 4, 2031 - 2041. ISSN: 2165-8714 https://www.eu-jer.com/ Implementing Project-Based Blended Learning Model Using Cognitive Conflict Strategy to Enhance Students’ Mathematical Spatial Literacy Rika Mulyati Mustika Sari * Universitas Pendidikan Indonesia, INDONESIA Nanang Priatna Universitas Pendidikan Indonesia, INDONESIA Dadang Juandi Universitas Pendidikan Indonesia, INDONESIA Received: March 1, 2022 ▪ Revised: May 31, 2022 ▪ Accepted: August 14, 2022 Abstract: High school teachers are mentors and facilitators that must be concerned about their students' formal thinking abilities. Students may not take a conservation task seriously because they perform operations without consulting. This necessitates modifying the learning process to increase student motivation. Therefore, this study aimed to examine students' mathematical spatial literacy through project-based blended learning with the cognitive conflict strategy. The study sample comprised 129 students, including 66 and 63 in the experimental and control classes, respectively, divided into the low, medium, and high levels. The findings showed that the experimental class students using project-based blended learning with the cognitive conflict strategy had higher mathematical spatial literacy than those in the control class using problem-based learning. Project-based blended learning with the cognitive conflict strategy and problem-based learning students at the high and moderate levels differed in their ability to increase their mathematical spatial literacy. However, low-level students are comparable in their ability to increase their mathematical spatial literacy. Keywords: Blended learning, mathematical spatial literacy, mathematics education, project-based learning. To cite this article: Sari, R. M. M., Priatna, N., & Juandi, D. (2022). Implementing project-based blended learning model using cognitive conflict strategy to enhance students’ mathematical spatial literacy. European Journal of Educational Research, 11(4), 2031- 2041. https://doi.org/10.12973/eu-jer.11.4.2031 Introduction The Coronavirus disease (COVID-19) pandemic has tremendously impacted many human life aspects, particularly education. According to the Ministry of Education, Culture, Research, and Technology, implementing Limited Face-to- Face Learning is dynamic. It could be implemented while adjusting to Micro-Community Activity Restrictions in each region. The Limited Face-to-Face Learning was implemented based on a Joint Statement of Four Ministers and the instructions of the Minister of Home Affairs Number 14 of 2021. This is according to Jumeri, the Director-General of Early Childhood Education, Primary and Secondary Education under The Ministry of Education and Culture, during a virtual education talk show on Thursday, June 24, 2021. Its implementation could occur in a district or city that is declared an orange zone and meets specific criteria. This policy restricts the days students attend school and their number in each class. For instance, students are only permitted to learn at school three times per week and study online on the remaining days. For health protocol implementation, only half the total number of students in each class are permitted to join Limited Face-to-Face Learning. As a result, principals and teachers seek appropriate and effective alternative teaching and learning methods, such as implementing a blended learning model. The model could be used with various methods and strategies relevant to the current situation (Saputri et al., 2021). According to Charman (as cited in Arifin & Abduh, 2021), blended learning mixes face-to-face education with online materials such as text, photos, diagrams, sound, and videos accessed by teachers and students over the internet. These findings support Bath and Brouke (2007) and Stein and Graham (2014) that the model combines online and face-to-face instruction, making it effective, efficient, and flexible to meet the learners’ needs. Also, Bath and Brouke (2007) stated that blended learning is a teaching system that combines face- to-face with technology-mediated instruction. Blended learning is an educator and students' collaborative effort to improve student learning experiences. Students enrich their learning experience and make it meaningful by experimenting with and evaluating different strategies and * Corresponding author: Rika Mulyati Mustika Sari, Universitas Pendidikan Indonesia, Indonesia.  rika.mulyatimustika@fkip.unsika.ac.id © 2022 The Author(s). Open Access - This article is under the CC BY license (https://creativecommons.org/licenses/by/4.0/).