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Math is taught totally different today than it was years ago. When I was in school they had 'New Math', which my parents also couldn't help me with. So maybe they change the way they teach math every few years just to keep parents from doing kids' homework. 8^)

I see a lot of graphing problems here, like slope/intercept problems. We didn't do that when I was in school. Then I realize all the kids have graphing calculators these days.

You should check and see if there's some free volunteer tutoring your sister can get.