When he gets tired with all the playing, he lays his head on one of my books (specifically the page that I would be currently reading. Funny, how he would know which one) and hugs and treats the scientific calculator as his teddy bear as you can see in that picture above.
I believe Chula has secret dreams of becoming either a mathematician, engineer or physicist. I have caught him reading books on advanced calculus, linear algebra, mechanics, and circuit theory.