This article presents an instructional strategy called Mathematical Bet Lines that was designed to promote classroom discourse and sense-making for all students, in particular English Language Learners. Introduced in Project AIM (All Included in Mathematics), a 40 hour professional development program focused promoting meaningful mathematical discourse, the Mathematical Bet Lines strategy supports comprehension of story problems by having students articulate to themselves and others their predictions regarding what is happening in the problem as it is revealed one sentence at a time. With Mathematical Bet Lines, as students make bets, the teacher facilitates students’ reflections on their own sense making of the story problem by asking follow-up questions. After describing the strategy, the article illustrates one teacher’s implementation of a lesson where she used the strategy with her second grade students. It concludes with other teachers’ reflections on using Mathematical Bet Lines in their instruction and helpful tips for classroom implementation.