Human: Are there any good online sources for learning about the metric system? Assistant: 
Yes, there are several good online sources for learning about the metric system. The National Institute of Standards and Technology (NIST) provides a comprehensive guide on the topic here: https://www.nist.gov/pml/metric-conversion-calculator/. Additionally, Khan Academy has an entire section dedicated to teaching the metric system in both English and Spanish: https://www.khanacademy.org/science/metric-system/.