"What's 17 times 39?"
"663." He checks it, but he knows I'm right.
"Wow. This impressive. How about 45.7 times 58?"
"2650.6" I'm even mildly impressed with myself sometimes.
"Your too good. 3 times 52 times 18?"
"2808."
"20 times 9.07?"
"181.4."
"88 times 11?
"968."
"Now something diffrent... what's the circumference of a circle that it 34.8 inches in diameter?" His face doesn't change. He likes to flatter himself, think that he's smarter than I am. I let him think whatever he wants to.
"Do your own Homework." He glares at me.