Free Rice is a cool site for kids who are trying to improve their vocabulary, English-as-a-second-language speakers who want to expand their word base, students of all high school subjects, and anyone who’s bored and wants to learn something.
Basically, Free Rice gives you a word, and you choose the synonym from 4 choices. The words get harder the longer you play (or so it seems to me).
Every time you get a word right, they donate 10 grains of rice toward feeding the hungry. That’s it! You don’t have to sign up, sign in, register… nothing. You just start playing, learn words, and the rice gets donated.
You can also change the subject to a variety of things: English grammar, chemistry symbols, literature, famous paintings, world capitals, basic math… the list goes on. Maybe I’ll learn some French!
(Meanwhile, they are missing a goldmine since there’s no Free Rice for SAT/ACT/GRE words. Maybe I’ll offer to make them one?)