One of Eliana's teachers just clued us in to a really great website. At http://www.freerice.com/ you can test your vocabulary, practice identifying countries of the world, quiz your math skills and more. And it's better than free! For each answer you get right, sponsors will buy 10 grains of rice for undernourished families through the UN World Food Program. Harvard developed the website and it's slick. The computer quickly figures out your knowledge level and works to increase it, recycling questions you get wrong so you can answer correctly the next time.
Eliana and I are both addicted to it. As we play the grains of rice pile up before our eyes! It's a better-than-free way to get ready for the GRE and the EOG (End-of-grade test for 3rd graders). And it accomplishes the unlikely task of uniting all 3 of my passions: my kids, academics, and missions!
Check it out!