Teaching mathematics means teaching learners to think – wrote Polya in How to Solve It? 1957. This paper intends to offer mathematics teachers suggestions for incorporating reading, writing, and speaking practices in the teaching of mathematics. Through explicit examples and explanations we intend to share ways of engaging students in deep learning of mathematics, especially using and producing written and oral texts. More specifically, we plan to broaden and deepen teachers’ understanding of strategies for guiding students’ thinking so that they grasp mathematical concepts and processes, and also bridge the divide between mathematical processes, and written and oral communication. This paper presents a core math lessons which provides numerous opportunities for the students to get actively engaged in the lesson and think about the new concepts, algorithms and ways of solving problems/ exercises. The lesson was designed for the 7th graders (13 year-olds). It was chosen to illustrate teaching by using reading and writing for understanding math processes. The teacher’s reflections after the lesson and some samples of the students’ work and feedback are included in the paper. The material in this paper is based on the author’s own extensive teaching experience; and her work in the Reading and Writing for Critical Thinking project in Romania.