Hi Melissa!
We list credits to help families gauge how much curricular weight is in each course. That said, families do things very differently. For instance, although high schoolers can take American History, some families remove the readings and exams for their middle school students to be able to follow along with the videos, take notes, and work on the portfolio and projects.
Some courses can be amplified—our Creative Writing courses could easily have literature added to them, academic papers written, etc. to build into a full language arts credit.
Ultimately, the choice of designating credits is up to the family because we neither keep records nor report courses to any homeschool regulating body.
If you want to see our suggested credits lined out by high school year, check out our Plan Your Year Guide here.