frhis Action Research study investigated the impact that teaching mathematics for conceptual understanding may have on students' engagement, confidence, and developing Mathematical Identitie~. The research was conducte:l in a mixed-ability Sixth Class ( 11 -12 years old) in a DEIS Band 2 Irish primary school, o;er two cycles with a single class group. The central research question asked: What impact can teaching with the aim of achieving conceptual understanding have on my student< ' engagement, confidence and developing Mathematical Identities? A targeted teaching intervention was designed, moving away from procedural instruction toward approaches prioritising meaning, reasoning and relevance. It incorporated three key strategies: embedding mathematical concepts in meaningful real-life contexts, explicitly addressing common misconceptions and integrating student Maths Journals as re flective tools. Data were collected through student journals, classroom discussion notes, the researcher's reflective teaching journal, and pre- and post-i ntervention administration of the adapted Abbreviated Maths Anxiety Scale (AMAS). Quali tative data were analysed using Braun and Clarke's (2006) Six-phase thematiC analysts framework, wh1le quanl!tat1ve AMA~ results provided supporting context. Findings revealed three overarching themes: (I) meaningful contexts enhanced student engagement, (2) conceptual understandi n~ builds FOnfidence, and (3) conceptual teaching requires signi ficant preparation and strong Mathematical Knowledge for Teaching. The intervention fostered more positive Maths Identities, with students increasingly viewing mathematics as understandable, relevant, and discussable. Conm10n Misconception strategies helped reduce Maths Anxiety by normalising error and reframing struggles as part of the learning process. AMAS results showed a general trend toward reduced anxiety, though some persistent discomfort with unpredictable testing remained. The study concludes that ~eachin~ for conceptual understanding can positively transform how students engage with and perceive mathematics. To strengthen this impact, the study recommends sustained professional development, greater emphasis on Mathematical Knowledge for Teaching in teacher training, and deliberate strategies such as using real-li fe contexts and addressing misconceptions directly.