Chris came to me with a blue, green and red crayon.

Handing me the red crayon, he said, "Make a '5' on this paper."

Then, with the green crayon, he said, "Make a '3' on the paper."

Thinking that I had it down, I took the blue crayon from his hand and asked, "Make a '1' now?"

"No, a '2'" he said. After that, I made a "1" and a "4" and we hunted for a brown crayon to make a "7".

The boy's obsessed.