I would like to make a hierarchy of courses under the subject of math, it would look something like this

Mathematic

- Numbers

Fractions

- Comparing fractions (Here goes all activities, quizes and so on)

- Adding fraction

...

- Algebra

Equations

...

- Geometry

Volume

...

I looked at metacourse but I could only do one level and it's not enough. Do I have to create separate courses to accomplish this?

It very much depends on how you want to implement this and who you want to access the subcourses. The most obvious solution would be to have a category called Maths -and then subcategories called Numbers, Algebra, Geometry and then individual courses in each of the subcategories. But perhaps if you can give more information then others can suggest more options? It also depends on how much information is to go in each of these topics -for example- could you simply have one course Algebra, but with two sections on variables and equations?

Thanks for your reply! Want I want to accomplish is that all users should have access to all information under math. I didn't realise that I could have different sections in a course. Then I could create a course called math and then create metacourses for Numbers, Algebra and Geometry. Could this work or are there other solutions?

That would work if you want to use Course meta link, yes. Do you have a particular reason for wanting to use this enrolment method?

You could use an upload csv file from your school's admin system or use a meta course.

https://docs.moodle.org/33/en/Course_meta_link

https://docs.moodle.org/31/en/Bulk_enrolments

Hope this helps,

Dave