yeah because you can (if you want to) just work on one or a few classes for like a year (or less), so then like if i do math science and history for like half a year, i would either do 2-3 classes of each, each day, or 1 of them all and like a chapter of a certain one, say you have an easy math chapter, you could do an entire chapter in one day, it just depends..now your brain is probably hurting.