Justin Bieber Teases Manager On 'Letterman'

Talk show host and teen phenom share quips over manager Scooter Braun's nickname.

Wearing a tuxedo T-shirt, Justin Bieber appeared on "Late Show With David Letterman" on Monday night to talk about fame, his 3-D movie "Never Say Never" and his lack of understanding of the U.S. education system.

When asked if he knows his IQ score and goes to school, Bieber said, "I don't know my IQ. I'm in school. I did school this morning. I do three hours a day and 15 hours a week. I'm in 11th grade. ... I don't know [what level that is in the U.S.], I'm Canadian," he laughed, adding that he's thinking of going to college someday.

"Right now [I'm] just kind of focusing on my music a lot. That's really important to me," he said. "This movie I have coming out. ... Most people just think they just put me together, some people just made me like I'm some factory machine, but this movie proves that I worked hard to get here and that's what I wanted to show."

Letterman then poked fun at Bieber's manager, Scooter Braun, for using his nickname instead of his given name of Scott. "Tell me more about Scooter," Letterman laughed.

"That's what me and my mom were thinking. Like, 'This guy named Scooter wants to sign me? How professional could this person be?' " Bieber laughed. "But it turns out he's got some creditability. He's not old and he's not young. He's like 30 ... he's really not — he's 29."

Letterman quipped back, "29 is OK, but 30 is too old to be calling yourself Scooter. That's the cutoff. We're done."

Braun later took to Twitter to laugh off the good-natured joke, writing, "Thank u David Letterman for allowing me to get texts from people I haven't spoken to in years telling me I might need to go by Scott now. I don't think so. lol. I'm Scooter until it's cool again. when is that u ask? when I'm grandpa Scooter. That's one cool grandpa."

It was the first of two appearances on "Letterman" this week as Bieber will be back Friday to do the Top 10 list.