My son flew through Singapore like it wasn't even there. Since then, I've been trying to find a curriculum that is a good fit (tried a few- he complains they're all "boring", meaning "too easy") and in the meantime I've been buying tons of workbooks for him to use. I don't like teaching through JUST workbooks because I feel it isn't complete. So, I signed up for EPGY and I love it (and so does he). I can set the level so it's challenging enough for him. The instructions are clear, verbal, and good for advanced kids- it's visual, which they need, yet it's stimulating. He can do as many lessons as he wants. They're in timed 20 minute intervals. Yesterday, he did 2, today he did 3. I feel it is completely WORTH my money because I can keep up with him and his needs without having to constantly go buy new stuff (a pain right now because our local homeschooling store is closed while they move). If he is past something, I can bump up his lesson level and move on. It's fun for him, too.