Question

according to recent curriculim guidelines, what percent of the class time should students spend in hands-on learning experiences?

Answer 1

What curriculum are you talking about?

Whatever answer they want you to provide can be found in your curriculum guidelines.

Answer 2

it depends on the subject. Music, art, chemistry, literature, basketball, and sex education all have different "hands-on" needs. Generally, we do not do much hands on in the latter subject.

In introductory chemistry, I tried 20 percent (not counting homework). In physics, it was more cognitive, I averaged about 10 percent hand ons.

Now the definition of hands on: is reading a hands on experience (consider literature, or poetry intrepretation). Is discussing hands-on?

Lots of experts will tell you guidlines on this, and rules of thumb, but in the end, it is mostly malarkey because of different definitions of hands on, are combined with differing teaching styles. Cognitive Contact time is a better measure of "hands-on" in my experience, that is, time the students brain is engaged in thinking and analyzing.
I found the best way to make contact time is to require students to take notes (NSL or Cornell Method), and GRADE the notes, providing feedback to the students, and counting the notebooks as a major grade. Effective notetaking engages the brain, and that is "hands-on" in any class.