The student becomes the teacher

Last night I sat down to help Mary with her homework. They were working on multiplying 2-digit by 1-digit numbers using mental math. That's the kind of thing I hate. 

She said, "Don't worry, Mom. I'll teach you. Here's the first problem, 46 x 7. How would you break down 46?"

"Four times 10, plus six," I dutifully answer.

"That's right! So we can write the first part like this: (40 x 7). And then you have 6 left over, so what do you do next?"

"Six times seven."

"Good job! So then we take (40 x 7) + (6 x 7) and what do you get?"

My mental calculator whirs and clicks until I say, a little too loudly, "322!"

"See, Mom? You did it. You are smarter than most of my slow-witted classmates."

Notice she said MOST. 

But I will take the math compliments where I can get them, thank you very much.