Every student at an Iowa elementary school is treated to a special birthday celebration that includes a free calculator, a rendition of the happy birthday song and a paddling from the principal.

Parent complaints have illuminated Principal Terry Eisenbarth's habit announcing student birthdays over the loudspeakers, after which the students proceed to his office to receive a calculator, some pencils and a swift tap from a padded hockey stick for every year of their lives. He calls them whammies.

An investigation into the practice is underway, the Desmoines Register reported.

Parent Steve Wernimont's three children have all received whammies. Two of them did not mind, but a third was very upset, he said.

I do not spank my kids at home on their birthdays, Wernimont said. That is not a celebration. It's being subservient to a dominating figure.