Learning mathematics is problematic for most primary school age children because mathematics is rote and the memorization of steps rather than an approach to seeing relationships that builds inquiry and understanding. Therefore, the traditional "algorithmic" way of teaching mathematics has not fully prepared students to be critical thinkers and problem solvers in mathematics. As a result, this study proposed a shift in the learning environment in mathematics. Number Talks provided this shift by allowing students to experience the autonomy of creating their own strategies to think critically and to approach problem solving tasks logically. For this reason, the researcher conducted a case study using a mixed-method approach to data collection analyze the effectiveness of number talks modeled by teachers to increase achievement in mathematics. Overall, student growth was achieved and an increase of student engagement help solidified the use of Number Talks taught effectively in a second grade ESOL classroom. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]