All right, I found the FreeRice website again in my favorites and decided to go check it out. It's not just vocabulary now and the donation amount is 20 grains of rice per correct answer. There's:
ART
Famous Paintings
CHEMISTRY
Chemical Symbols (Basic)
Chemical Symbols (Full List)
ENGLISH
English Grammar
English Vocabulary
GEOGRAPHY
Identify Countries on the Map
World Capitals
LANGUAGE LEARNING
French
German
Italian
Spanish
MATH
Basic Math (Pre-Algebra)
Multiplication Table
Tip: You can rack up lots of grains with the Multiplication Table and make yourself faster at math at the same time.