Hi Bill, I also have an 11 year old homeschooling for grade 6. You can use the website however you like, but what I've found for my daughter is that it is better if we cover the material in a logical way first, and then practice the skills we've been working on (use the Coach "Recommendations") and level up with Mastery Challenges.

What this looks like in practice:

1) Use the Topic view to work through a section of the curriculum

This is the  link to the content for the whole of the 6th grade mission https://www.khanacademy.org/math/cc-sixth-grade-math

And you might decide to work on, for example, Arithmetic Operations

 https://www.khanacademy.org/math/cc-sixth-grade-math/cc-6th-arithmetic-operations

Working through the content in order, my daughter will learn from the videos and practice the questions on this screen.

2) As a Coach, go into Student Progress section, and "Recommend" the skills that your child has just learned.

This will make these skills turn up as top priority in their Mission dashboard (on the right hand side) so they can practice them some more. 

3) Once your child has learned and practiced the skills, the skills will be tested in the Mastery Challenges, which will allow them to "level up" in those skills.

https://www.khanacademy.org/mission/math?ref=current_missions

The Mastery Challenges will also include old skills they have learned in the past, to make sure they still remember them, and some new skills are thrown in as oddballs, which your child may or may not know how to do.

Of course, if your child already knows some of the content, you don't need to make them watch through all the videos etc. There is a difference between learning new skills versus being tested/credited for skills they already know. 

If your child already knows some of the grade 6 content, you could work down the list on the left side of the page "Skill Breakdown".

Start with the Mission Foundations to make sure there are no gaps in your child's foundational knowledge for the grade 6 unit.  Click on each grey square to "practice" the skill, and it will turn light blue once practiced.

Once skills have been practiced, they will take priority in the Mastery Challenge - which is where skills are tested and level up.

Work through each of the skill topics. Skills go from easy to hard from left to right (or if there is more than one line, the ones on the second line are harder than those on the top). Sometimes if you do a hard one first and get it right, easier foundational skills will automatically be credited as being known.

Weigh up what will work for your child best, as they all have different personalities and preferences. My daughter gets disheartened if she gets questions wrong, so we've found for her it is better to give her a good set up and practice rather than risking skills she doesn't know sprung on her. But other kids might get bored or frustrated if they have to sit through videos and questions that are too easy for them.

Hope that helps?

Just want to drop in and say Thank You for such a thoughtful response, Luci!  It's always so helpful to hear specific use cases of how other parents use Khan Academy with their children.

Thanks so much, Luci, So awesome to see in such detail how someone else is using the tools here. I'll write up my experience too at some point (when we get really organized) so others can see as well. I really appreciate the time you put into this.

There is not just any right way. You have to cater it to the needs of a student, which is what Khan does best!