Article Code: 5248603 Authors: Gaspar, Angeline Title: Differential Effects Of Mother Tongue And English Language As A Medium Of Instruction On Pupil’s Numeracy Skills Journal: RECENT EDUCATIONAL RESEARCH Volume: 1 Year: 2023 Issue: 2 Article Number: 5248603 URL: http://guinnesspress.org/publication/journal/rer/5248603 ISSN: 2996-2366 Abstract: This Study Explores The Differential Effects Of The Mother Tongue And English Language As Mediums Of Instruction On Pupil’s Numeracy Skills. The Objective Is To Determine If There Are Significant Differences In Posttest Gains Between A Control Group Taught In The Mother Tongue (Tagalog) And An Experimental Group Taught In English. The Researcher Also Aims To Identify The Factors And Challenges Faced By Teachers Using Both Languages As Mediums Of Instruction. Using A Mixed-Method Design, The Researcher Collected Quantitative And Qualitative Data. Sixty Pupils Each Were Randomly Selected For The Control And Experimental Groups From Laiya Elementary School. Pretest And Posttest Scores Were Analyzed For The 120 Grade 3 Pupils. The Results Revealed That The Experimental Group Taught In English Achieved Significantly Higher Posttest Results Compared To The Control Group Taught In The Mother Tongue. Qualitative Data Was Obtained Through Interviews With Grade 3 And Grade 4 Teachers, Highlighting Factors Such As Poor Study Habits, Lack Of Interest And Motivation, Limited Parental Involvement, And Low Reading Comprehension Levels As Barriers To Improving Numeracy Skills. Furthermore, Teachers Faced Challenges When Using Both Languages, With Grade 3 Teachers Struggling To Translate Mathematical Terms Into The Mother Tongue And Grade 4 Teachers Finding It Difficul To Assess Pupils’ Prior Knowledge Due To Their Strong Exposure To The Mother Tongue. Transitioning Between Languages, Especially In The First Quarter, Created Confusion And Hesitation Among Pupils. Limited English Vocabulary Acquired During Primary Years Further Hindered Understanding And Comprehension. To Enhance Numeracy Skills, Teachers Emphasized The Need For Motivation, Additional Activities, Integration Of Numeracy Across Subjects, Improved Reading Comprehension, Parental Participation, Varied Teaching Methods, And A Conducive Learning Environment. The Study Highlights The Importance Of Selecting An Appropriate Language, Establishing A Language-Rich Environment, Incorporating Cultural Relevance, And Integrating Language And Mathematics Instruction To Foster Deep Understanding, Critical Thinking Skills, And Confidence In Students As Proficient Mathematicians. DOI: 10.59762/rer904105361220231220142944