Thanks for your feedback! All feedback is really useful to us, as it helps us to continue to polish the product. The articles themselves are crowd-sourced, and they certainly show signs of being a community that is still growing. It's possible to create richer articles like this one:
https://www.expii.com/t/gravity-weight-642The main point of our post tonight was to share the current product of the Topic Map. As the rest of the site continues to grow, we hope that you will soon learn about it as a useful resource.
Regarding the split of Algebra 1 and Algebra 2: we fully agree that math should be more connected. We actually experimented with that here, in the "Theory" section of "Math". You can find that by clicking into "Algebra Revisited", which you can also find by first going here:
https://www.expii.com/t/2829
and then clicking on "Topic Map" to see a fully connected version of Algebra. This is much more theoretical though, and does not align so easily with standards used in mainstream schools. We chose to make the main sections of our maps align with standards so that they could be more immediately useful for the mainstream audience. However, we ourselves are a bunch of enthusiasts who love to think about how to push the envelope. :)