Article About Smithsonian Error

This Yahoo! News article about an error has a fun ending:

ALLEGAN, Mich. - Is fifth-grader Kenton Stufflebeam smarter than the Smithsonian?
On a winter break trip with his family to the Smithsonian Institution's National Museum of Natural History, the 11-year-old southwestern Michigan boy [Kenton Stufflebeam] noticed that a notation, in bold lettering, mistakenly identified the Precambrian as an era.
Since it opened in 1981, millions of people have paraded past the museum's Tower of Time, a display involving prehistoric time. Kenton was the first to point out the error.
Kenton, who lives in Allegan but attends Alamo Elementary School near Kalamazoo, said his fifth-grade teacher, John Chapman, had nearly made the same mistake about the Precambrian in a classroom earth-science lesson before catching himself.
"I knew Mr. Chapman wouldn't tell all these students" bad information, the boy told the Kalamazoo Gazette for a story published Wednesday.
So Kevin Stufflebeam took his son to the museum's information desk to report Kenton's concern on a comment form.
Last week, the boy received a letter from the museum acknowledging that his observation was "spot on."
"The Precambrian is a dimensionless unit of time, which embraces all the time between the origin of Earth and the beginning of the Cambrian Period of geologic time," the letter says.
The solution to the problem would not involve advanced science but rather simply painting over the word "era," the note says.
While no previous visitors to the museum had brought up the error, it has long rankled the paleobiology department's staff, who noticed it even before the Tower of Time was erected 27 years ago, said Lorraine Ramsdell, educational technician for the museum.
"The question is, why was it put up with that on it in the first place?" Ramsdell said.
Excited as he was to receive the correspondence from museum officials, he couldn't help but point out that it was addressed to Kenton Slufflebeam. In Allegany.