Katie Carden's English students spend part of their class time each week in the library answering vocabulary and grammar questions on the website www.freerice.com.
For each one they get right, 10 grains of rice are donated through the World Food Programme.
Over 4.3 million people have been fed because of Freericers since 2007, according to a recent blog entry on the site.
Carden heard about Freerice from a friend who is also a teacher. She left it as an assignment when she had to miss school one day last week.
"One of my classes had to go to the library. I sent the activity to the librarian, and she said they loved it," Carden said.
Carden said the website is preparing her students for their graduation and college entrance exams.
It is also teaching them some new words that they can use in their term papers and future job interviews.
The questions on Freerice get more difficult every time the students get three in a row right. There are over 12,000 words divided into 60 levels.
Carden's classes may know the meaning of "incomplete" at level one, but will they be able to define "collimate" at level 60?
When they get a question wrong, the site provides the correct answer and asks the question again later so they will remember it.
If they get tired of English, they can answer questions dealing with art, chemistry, geography, math and foreign languages.
They can also click on various links to learn more about world hunger and places where their rice is being donated.
All rice raised through the site this month is going to help the people of Haiti.
Some of Carden's students have found the site to be so addictive that they log on at home.
Carden is pleased with their enthusiasm.
"It breaks the monotony of 'Sit down. Get out your book.' for them," she said.