Thanks for the links Ania! Sadly, I am not the math person in the family, you may remember my high school said I had "math anxiety" and was not required to take any more math past Algebra I! I may order the first Aops set for my husband to look at and decide when to introduce it to DD8.
Interestingly, the older I get, the more interested I am becoming in more advanced math concepts, maybe influenced by DD and DH's interest!