The Low Cost of Doing Good
It often takes only a tiny amount of money to make a big difference. Bed nets, which protect sleeping people from malaria-infected mosquitos, "cost seven dollars," says Sachs. "They sleep two people, and they last for five years. That's 70 cents per person per year." Preventing painful stomach parasites is even cheaper. "One chewable pill taken once or twice a year costs two cents per tablet," Sachs says.

The World Food Programme (WFP), based in Rome, Italy, tackles the problem of hunger by feeding children in schools. The WFP runs a global school-feeding campaign that helps kids get food and stay in school. The promise of a good meal helps to draw children to school. And when kids get an education, they are better able to help themselves, their community and their country battle poverty. Last year, the WFP fed nearly 17 million kids in 72 countries. It costs only 19 cents a day for the WFP to give a child a nutritious meal at school. Just $34 can feed a child for a whole school year!

By the Numbers
$7: The cost of a bed net that will protect two people against malaria for five years

19¢: The price of a healthy meal for a school child in a poor country

2¢: The cost of a pill to treat stomach parasites in a child in Africa

$100: The price of 740 doses of measles vaccine

$25: The cost per month of treating one child who has AIDS

60¢: buys water purification tablets to treat 5 gallons of water.