Play and feed hungry people

At FreeRice we could play games and for each answer you get right, they donate rice via WFP. There are 6 subjects: Math, Arts, English, Chemistry, Geography and Languages. It's fun and it's also helping others while brushing up your knowledge.

One good answer is equal to 10 grains.
There are 48 grains of rice in a gram.
A person eats on average 400grams a day.