Four Point Oh Dear

(My mom, dad, one of my sisters and I are sitting in the living room talking with a popular TV show on in the background.)

Me: “Did you know that person who plays [Character] has a 140 IQ?”

Sister: “Wait, but isn’t like a 4 a good IQ?”

Everyone: *stares at her*

My Sister: “Oh. Wait. No, that’s GPA, isn’t it? Yeah, 4.0 GPA is good!”