Genius, say others.
But entirely normal for Jacob, a child prodigy who used to crunch his cereal while calculating the volume of the cereal box in his head.
"Whenever I try talking about math with anyone in my family," he said, "they just stare blankly."
So do many of his older classmates at Indiana University-Purdue University Indianapolis, who marvel at seeing this scrawny little kid in the front row of the calculus-based physics class he has been taking this semester.
When Jacob Barnett first learned about the Schrödinger equation for quantum mechanics, he could hardly contain himself.
For three straight days, his little brain buzzed with mathematical functions.
From within his 12-year-old, mildly autistic mind, there gradually flowed long strings of pluses, minuses, funky letters and upside-down triangles -- a tapestry of complicated symbols that few can understand.
He grabbed his pencil and filled every sheet of paper before grabbing a marker and filling up a dry erase board that hangs in his bedroom. With a single-minded obsession, he kept on, eventually marking up every window in the home.