So after I put Suzi down for a nap, I pulled out Isaac and Sophie's packets and they got busy. Isaac had a TON of math to do - about 50 addition problems on one side of a sheet, and 50 subtraction problems on the other. While he was working on it, he threw his pencil down and said, "This is too hard!"
"You know," I told him, "The brain is like any other muscle in your body and when you work it so hard that it hurts, it becomes stronger and you become smarter. If you keep this up, you'll be as smart as me and daddy."
Isaac asked, "Together?"