"Alexa, what's 5 minus 3?" A 6-year-old boy recently asked that question in a video, which went viral on Twitter with more than 8.5 million views. He leaned over his homework as his mother hovered in the doorway. Alexa, Amazon's voice-activated assistant, delivered a quick answer: 2. "Booooy," the mother chastised her son. It's cute, but it raises a question that's been on the minds of many parents and educators lately: How do virtual assistants like Alexa, which are increasingly common in households, affect children's learning experiences?