Ariani, Agus Martina, The Use of English as the Medium of Instruction in Teaching Mathematics and Science at SD Tunas Bangsa Full Day School Pare, Kediri, English department, faculty of education, STAIN kediri,2012. First advisor is Drs. Agus Edi Winarto, M.Pd Second Advisor is Nur Afifi M.App.Ling. Keywords : the use of English, the medium of instruction This thesis is a descriptive qual…