The Geometry of Butter

My oldest daughter is an enigma.  Sometimes she's all "like, you know" and "OMG" (the G being gosh in our house).  Then there are times when you would think she's a Mensa candidate in a little kid body.  She sometimes talks like she can't imagine what it would be like to only be a 9 year old girl. 

So, for some reason unbeknownst to me, my kids claimed they didn't know what a stick of butter was.  Granted, for table butter, we usually go with the tub and I reserve the sticks for cooking, but still.  So I was trying to describe to them what a stick was vs. the tub, when my oldest exclaims in sudden understanding, "oh, you mean it's a rectangular prism!" 

Yes.  That's what I meant.