English has seven words that behave very strangely when you change them from the singular to the plural. These are called THE MUTANT PLURALS of English. They're super cool. Practice this yourself on Khan Academy right now: https://www.khanacademy.org/humanities/grammar/partsofspeech/grammar-nouns/e/irregular-plural-nouns--mutant-plurals?utm_source=YT&utm_medium=Desc&utm_campaign=grammar Watch the next lesson: https://www.khanacademy.org/humanities/grammar/partsofspeech/grammar-nouns/v/foreign-plurals-grammar?utm_source=YT&utm_medium=Desc&utm_campaign=grammar Missed the previous lesson? https://www.khanacademy.org/humanities/grammar/partsofspeech/grammar-nouns/v/irregular-plurals-the-base-plural?utm_source=YT&utm_medium=Desc&utm_campaign=grammar Grammar on Khan Academy: Grammar is the collection of rules and conventions that make languages go. This section is about Standard American English, but there's something here for everyone. ... https://www.youtube.com/watch?v=VdLOP9teko4 Note: All Khan Academy content is available for free at (www.khanacademy.org)

What is a “strong password”, exactly? What are some ways that you can create a password that is strong and easy to remember? To learn more about how you can keep yourself safe while on the Internet, visit: internet-safety.khanacademy.org ... https://www.youtube.com/watch?v=svrOhWyp09c Note: All Khan Academy content is available for free at (www.khanacademy.org)

Introduction to the cross product. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/science/physics/magnetic-forces-and-magnetic-fields/magnets-magnetic/v/cross-product-2?utm_source=YT&utm_medium=Desc&utm_campaign=physics Missed the previous lesson? https://www.khanacademy.org/science/physics/magnetic-forces-and-magnetic-fields/magnets-magnetic/v/magnetism-2?utm_source=YT&utm_medium=Desc&utm_campaign=physics Physics on Khan Academy: Physics is the study of the basic principles that govern the physical world around us. We'll start by looking at motion itself. Then, we'll learn about forces, momentum, energy, and other concepts in lots of different physical situations. To get the most out of physics, you'll need a solid understanding of algebra and a basic understanding of trigonometry. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. ... https://www.youtube.com/watch?v=zA0fvwtvgvA

Mysterious negative numbers! What ARE they? They are numbers less than zero. If you understand the nature of below zero temperatures, you can understand negative numbers. We'll help. Practice this lesson yourself on KhanAcademy.org right now: https://www.khanacademy.org/math/pre-algebra/negatives-absolute-value-pre-alg/add-sub-negatives-pre-alg/e/number_line_2?utm_source=YT&utm_medium=Desc&utm_campaign=PreAlgebra Watch the next lesson: https://www.khanacademy.org/math/pre-algebra/negatives-absolute-value-pre-alg/add-sub-negatives-pre-alg/v/number-line-3-exercise-example?utm_source=YT&utm_medium=Desc&utm_campaign=PreAlgebra Pre-Algebra on Khan Academy: No way, this isn't your run of the mill arithmetic. This is Pre-algebra. You're about to play with the professionals. Think of pre-algebra as a runway. You're the airplane and algebra is your sunny vacation destination. Without the runway you're not going anywhere. Seriously, the foundation for all higher mathematics is laid with many of the concepts that we will introduce to you here: negative numbers, absolute value, factors, multiples, decimals, and fractions to name a few. So buckle up and move your seat into the upright position. We're about to take off! About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. ... https://www.youtube.com/watch?v=Hlal9ME2Aig Note: All Khan Academy content is available for free at (www.khanacademy.org)