The purpose of our research was to determine what impact participating in regular number talks, informal conversations focusing on mental mathematics strategies, had on elementary students’ mental mathematics abilities. The research was conducted in two urban fourth grade classrooms over a two month period. The data sources included a pre- and post-questionnaire, surveys about students’ attitudes towards mental math, a pretest and a posttest containing addition and subtraction problems to be solved mentally, teacher reflective journals, and student interviews. The results of our research indicate that participating consistently in number talks had a positive effect on students’ mental mathematics abilities and the problem solving strategies they were able to articulate. Recommendations based on the results of the investigation include adopting brief number talks as an essential component of elementary mathematics curricula, thus allowing students many opportunities to solve problems mentally and to discuss their reasoning.