Both cognitive neuroscience and the learning sciences are roughly 25 years old. Both address fundamental questions about how people think - and learn to think - about complex domains such as mathematics and science. This raises the question of what, if anything, cognitive neuroscience has to offer the learning sciences? This chapter first reviews the dominant methods of cognitive neuroscience. It then sketches a view of thinking and learning in the brain. Next, it presents a case study of the insights that cognitive neuroscience is providing into mathematical thinking, learning, and instruction. Finally, it considers obstacles to applying cognitive neuroscience findings to research problems in the learning sciences.