Chapter 16 and 17 in the AskDrCallahan homeschool Algebra course are considered optional. We consider these algebra lessons optional because chapter 16 covers inequalities which is material you will see again in later courses (see in the immediately following course if you’re using our typical math sequence) and then Chapter 17 covers number sequences, which is material you will never see again unless you choose an extremely technical (and rare) study option. Even if you are this rare student, you reach this technical level at college, and they teach you this concept from the ground up. Both chapters contain good math material, so feel free to use them, but you do not have to cover them at the Algebra 1 level.
Also, you should note that you are still getting an excellent Algebra course without those chapters, and you are not hurting yourself if you choose to use them. They are not more advanced than an Algebra 1 student can handle, they are —just as they are labeled—optional. Good if you want to use them, but you don’t have to.
