Happy Mole Day from Khan Academy!

As a chemistry nerd, Mole Day is one of my favorite days. What’s a mole, you ask? It’s another name for Avogadro’s number, 6.022 × 1023. And 1023 is today’s date - 10/23 - see how we did that?! Chemists, so creative. So really, it is just a number like a “dozen” or a “pair.” It is actually a really really big number that we could also write out as 602214129000000000000000. In fact, did you know that Avogadro’s number is more than a million times as big as the number of seconds since the Big Bang?

Chemists use moles to make counting easier, like when talking about numbers of atoms or molecules. We can actually count anything in terms of moles, like water molecules. How many molecules are in a cup of water, which holds about 240 g of water? It turns out that a cup of water contains about 8,000,000,000,000,000,000,000,000 molecules of water. That’s a lot of molecules and chemists don’t want to write that out every time, so we can also just call it 13 moles of water instead.

You can learn more about Avogadro’s number and lots of other fun chemistry topics on Khan Academy. Happy Mole Day!

- Yuki, Khan Academy Chemistry Fellow and fan of moles, both animal and chemical


New biology resources debut on Khan Academy

We’re excited to share that, with support from the Amgen Foundation, we’re making lots of new videos, articles, and quizzes to help students taking biology courses at the AP and introductory college levels. Several areas of biology are already complete, and we’ll continue adding more throughout this school year and beyond.

Here’s a more detailed list of the biology topics we’ve revamped so far:

Chemistry of life
Water, acids, and bases
Properties of carbon
Structure of a cell
Membranes and transport
Cellular and molecular biology
Energy and enzymes

In addition to funding from the Amgen Foundation, scientists from the foundation’s parent company, the biotechnology firm Amgen, are volunteering their time to provide expert quality reviews of our new biology resources to ensure they’re top-notch. “Khan Academy has shown how to leverage technology to put an excellent education in the hands of every student,” says Eduardo Cetlin, president, Amgen Foundation. “We are proud to support Khan Academy in the development and launch of this exciting new biology content and hope these resources will help nurture, engage and inspire many future scientists in the U.S. and across the globe!”

We’re super lucky to have Emily Abrash on our team to lead all of this new biology work. Emily joined us after completing a PhD in biology at Stanford, where she was a biology teaching assistant. Emily also just so happens to be an intrepid cyclist who bikes dozens of miles to work each day!

Stay tuned for updates on new content in other subjects. There’s way more coming soon!


Khan Academy and BELL team up to help kids code

Guest post from Michael Sikora, Director of Communications at BELL (Building Educated Leaders for Life)


“Pick two:  Sculpture, Drawing, Team Sports, Coding, Improv Comedy, Drama, Film Appreciation.”

When the time came for Paolo to select the enrichment activities he wanted to participate in this summer, the opportunity to take a coding class jumped out at him.

“I didn’t really know anything about coding before this summer,” said Paolo. “But I wanted to try it out because I wanted to know how people made video games.”

Along with his peers at Davidson Middle School in San Rafael, California, Paolo learned some of the basics of computer programming as part of his summer learning experience thanks to a collaboration between BELL (Building Educated Leaders for Life) and Khan Academy.

This was the first summer that students – or, “scholars” as they are recognized in BELL’s programs – encountered Khan Academy’s free coding course, Intro to JavaScript, as a summer elective.  The two nonprofit organizations are also expanding individualized learning opportunities for scholars through Khan Academy’s free math resources, based on scholars’ individual needs identified by the results of the pre-program computer adaptive assessments.

Here’s how it all works:  the school leaders and teachers who deliver BELL’s summer learning programs for scholars in grades K-8 can choose to integrate the free Khan Academy math and coding resources into their summer learning plans, based on variables such as scholar needs and technology access.  BELL provides training, instructor guides and resources (such as primers, video tutorials, and sample reports) and ongoing coaching via email and webinars. Teachers, scholars, and parents can all access the math and coding resources, and continue using them after the summer program concludes. In fact, at a site visit at Davidson, Emily Radwin, BELL’s Learning and Assessment Systems specialist, was able to hear from both scholars and staff that many scholars were choosing to work on coding projects at home and on the weekends.

The Khan Academy coding curriculum also allows scholars to work collaboratively in pairs, and has opportunities for scholars to have “free time” and use what they’ve learned to work on free-form coding projects.

“One of the most rewarding things for me is to see the class so engaged by the curriculum,” said Anne Carmin, a teacher at the Davidson Middle School. “Scholars are excited to be here.”

You read that correctly: the opportunity to learn about computer programming, while also honing their academic skills, motivates scholars and makes them excited to spend a big part of their summer – five weeks, five days per week, six hours per day - at school.

“I like that we get to try out new things each day,” said Hendy.  One of his favorite activities was creating clouds with his newfound coding skills.  Jossie agreed.  “I like that we get to try new things here at BELL. When I started with coding, I didn’t know anything about the subject.  I started asking for help, and now I really like it.”

Read more about the summer learning scene in San Rafael in this article by the Marin Independent Journal, and learn more about how the math and coding activities work in BELL’s summer learning programs.  

Have you used Khan Academy’s Intro to JavaScript curriculum? Tell us your story in the comments below!


Khan Academy in your pocket — new apps available for iPhone and now Android!


Download for Android — Google Play

Download for iPhone — App Store

“A free, world-class education for anyone, anywhere.” This mission inspires us day in, day out, and we’ve seen over 30M students sign up on Khan Academy to learn almost anything for free. We know you love using Khan Academy more and more on your phones: in fact, over 30% of our sessions are now on mobile devices. We believe strongly that unlocking the potential for anyone, anywhere to learn on 2B+ smartphones worldwide is just getting started. Today, we’re excited to announce a couple steps toward a better Khan Academy in your pocket!

Khan Academy on Android and iPhones

Today Khan Academy is releasing our first Android app along with a redesigned iPhone app!

We built these apps to make on-the-go learning faster and easier:

- You can learn anything — for free: Over 10,000 videos and explanations at your fingertips in math, science, economics, history, and much, much more

- Quickly find what you need: Redesigned navigation and search make it faster to find what you want  

- Keep learning even when you’re offline: Bookmark your favorite content to “Your List” for easy access, and download it to keep learning even when you’re not connected to the internet.

- Pick up where you left off: Your learning syncs between your Android/iPhone and, so your progress is always up-to-date

Download them today:

Android — Google Play

iPhone — App Store

And… stay tuned in our Android beta community and our blog to be the first to know when exercises and other new features are on the way!

Khan Academy in 5 languages on iPad and iPhone

Expanding to mobile platforms is just part of our mission to bring high-quality content to learners around the globe. Today we’re excited to announce that our iPad app and new iPhone app are now available in Spanish, Brazilian Portuguese, French, Norwegian, and Turkish. Catch all the details on our international blog.


Khan Academy and Breakthrough Prize launch the Breakthrough Junior Challenge

Calling all scientists, mathematicians and filmmakers, aged 13-18! Today, in partnership with Breakthrough Prize, we are launching the Breakthrough Junior Challenge.

Submit a video (at most 10 minutes) that explains a challenging and important concept or theory in mathematics, life sciences, or physics and you could win a $250,000 scholarship - with $50,000 for your teacher, and a state-of-the-art $100,000 science lab for your school.

The winner will also be invited to the televised red carpet 2016 Breakthrough Prize ceremony in Silicon Valley, where the prize will be awarded, and the winner will meet today’s superstars of science from Silicon Valley and Hollywood.

The deadline for submissions is October 7, so register today at, where you can find all the details.