A penny war is a common fundraising technique.This technique is commonly used in school for kids are usually more competitive and enthusiastic than adults.
In a penny war, two or more groups compete to win a fundraising competition. Each group has a bucket for collecting coins or dollar bills. The value of any pennies collected by a group count positively toward that group's point total, while the value of other coins or dollar bills are subtracted. Hence, in a competition between Group A and Group B, a contributor who wants Group A to win will place pennies into Group A's bucket and nickels, dimes, quarters, or dollar bills into Group B's bucket.
At the end, a winner among groups is declared, and all the proceeds are donated to a specified charity.