"I thought it would be too advanced for my 3rd and 4th graders, but they were instantly into it. I'm very compulsive about it, I really get into it, and so are they!" Heffernan said.
It's called FreeRice.com. Odd, until you hear the twist. Click on a correct word definition - and boom - you've just donated 10 grains of rice to combat world hunger.
CBS News science and technology correspondent Daniel Sieberg asked kids in Heffernan's class where the rice goes to.
"To other countries," the class said. "To people who need it."
"You just gotta get the answer right and you learn more and you help people at the same time," said 9-year-old Mallory Pyke.
The man who's connecting these kids from America's heartland to the rest of the world is also from Bloomington. And here's a question for you. Which word best describes him:
Or how about D) All of the above?
Ten grains of rice, by itself, it's very little. But when you combine it with millions of people - each giving ten grains - it can turn into hundreds of metric tons.
John Breen is a computer programmer who's long been interested in poverty and global issues. His outside-the-box idea has soared since its debut just six weeks ago.
One hundred and eighty-eight million grains of rice were donated yesterday, Sieberg said to Breen.
"Yeah, in total it's just over 1.5 billion, and that's just in a month. I think it shows you that people want to do something about world hunger."
"Getting people, and young people, to learn about the problem of hunger and poverty I think that's really where John has struck it rich for us," said Natalie Vaupel of the U.N. World Food Program.
Freerice.com is an international, viral sensation. Folks from Thailand to Germany and India are just as enthusiastic as those 4th graders in Bloomington. They may not be changing the world, but they will be improving thousands of lives, all with a simple, collective, click of a mouse.
An update from Daniel Sieberg: According to Breen, after the CBS Evening News story ran Thursday night, 20 million correct answers were clicked, bringing the donation total to more than 2 billion grains. Visitors to the site included, of course, those dedicated schoolkids from Bloomington, Ind.
The U.N. says the rice will be in cyclone-ravaged Bangladesh soon, with more likely on its way to drought-stricken Africa.