And, if you choose to create a free account, your learning syncs with, so your progress is always up-to-date across all your devices. Pick up where you left off: Tailored to your current learning level, our mastery system gives instant feedback and recommendations on exactly which skills and videos to try next. Keep learning when you're offline: Bookmark and download your favorite content to watch videos without an internet connection. Follow along with what you're learning in school, or practice at your own pace. Sharpen your skills: Practice exercises, quizzes, and tests with instant feedback and step-by-step hints. Study math, science, economics, finance, grammar, history, government, politics, and much, much more.

Learn anything, for free: Thousands of interactive exercises, videos, and articles at your fingertips. Whether you're a student, teacher, homeschooler, principal, adult returning to the classroom after 20 years, or a friendly alien trying to get a leg up in earthly biology - Khan Academy's personalized learning library is available to you, for free. Or, if you're feeling particularly adventurous, learn how fire-stick farming changes the landscape of Australia.

Get a head start on next semester's geometry. Spend an afternoon brushing up on statistics.

Khan academy app download