As presented, at least two values are presumed to be in conflict. The first is the mitzvah of “veshinantem levanekha” – to Jewishly educate our child(ren) with a Torah education. Of course, providing our child(ren) with liberal arts, math and science education is also fundamental to raising literate, culturally attuned and pragmatically skilled, and therefore, employable, self-reliant human beings. While a “secular education” can be accomplished through a good public school education, it is also assuredly achieved through a good Jewish Day School education, as well. Furthermore, for many a child, a public school’s social environment may undermine the raising of a Jewishly committed, halakhically practicing and Torah literate Jew. Thus, without a doubt, training our child(ren) for a life of Jewish observance and engagement with Torah and Mitzvot, along with equipping them with a quality “secular education,” is best and most thoroughly accomplished through sending our child(ren) to Jewish day school.
You present an interesting dilemma, one with which I have personally grappled as a Jewish parent of school-aged children. What you have here is a conflict between two goods.