This paper posits that, as educators' attention turns to elementary mathematics as preparation for algebra, it is important to begin by examining the kind of elementary mathematics content teaching that is aligned with reform. The paper calls for a close examination of students' development of operation sense. The role of children's engagement with the four basic operations in their preparation for algebra is also discussed. One method of data collection used in this study is episode writing. Six of the scenarios presented in this paper are taken from episodes written by teachers in a National Science Foundation teacher-enhancement project known as Teaching To the Big Ideas. Although the question of how elementary education can prepare students for algebra is addressed here, teachers at other levels still need to be prepared to help their students begin to make meaning of the language of algebra. Implications of this work include the idea that other notional systems such as diagrams, graphs, and tables in written and electronic forms are important for students to understand. Contains 62 references. (DDR)