Smarterer.com is a site where you can take and create multiple-choice tests. One caveat is that created tests are open for any Smarterer member to take and to add to. So if you create a test about basic math, as I did, you may discover that the interpretation of "basic math" is very different from what you anticipated.
My basic math test became popular fairly quickly. It soon had close to 500 questions, even though I had only created about 30. The owners of the site asked if I'd be willing to take on the role of "Professor" for that test. As the Professor, I review questions and can now remove questions that don't fit into my definition of "basic math".
Many people had added algebra and geometry questions into the mix. When I removed those items, I placed them in new tests. The algebra test is ready to go, but the geometry test is not quite done yet. You need 20 questions before the test goes "live".
If you'd like to test you skills on a few random questions, check out my two tests. You can compete with others to make it on the leaderboard. You can also comment on any of the questions. Please do leave a comment if you see one that shouldn't be there or isn't correct. Have fun!