has a free moment, she'll use it to read. and teachers ask students to track the speaker to make sure they're really listening and engage. >> tracking melvin? >> it's an immersive approach to learning, and it works. >> all right. cube root of 64? one clap for crystal. cube root of 27. >> 3. >> one clap for adam. square root for 36. >> 6. >> one clap for morgan. >> who is president during world war i? double snaps. nice. second question. westward expansion. many americans justified it based on this idea. double snaps. third question. she was an anarchist critical of the government and deported in the early 1920s to russia. who was she? adriana? double snaps. two more.