Algebraic thinking is an essential component of the K-12 mathematics curriculum. Early algebra focuses on the overall numeric structure (Kaput, 2008; Kieran,2018; Kieran et al., 2016) which focuses on the noticing of arithmetic patterns leading to generalizations supported by justification, reasoning and justifications (Blanton, 2008; Blanton et al., 2018; Kieran, 2018; Kieran et al., 2016; Kieran et al., 2017; Kieran, 2018). This study focuses on investigating the conceptualization pre-service teachers develop as they participate in an elementary mathematics methods course with an intentional focus on algebraic reasoning, lesson planning, and use of technology. An additional component of supporting student algebraic thinking through the use of technology and the use of the Technological, Pedagogical, and Content Knowledge (TPACK) (Mishra & Koehler, 2006) was used to document shifts in pre-service teachers' developing knowledge. Through mixed methods analysis, this study provides insight into the course development and sequencing of mathematics content, pedagogy, and technology to support pre-service teachers' learning of algebraic thinking and lesson planning. Practical implementations for algebraic thinking and teaching of elementary mathematics methods courses are discussed, as well as the theoretical implications for the TPACK framework. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]