"That made sense!" Wen Ning says, as he would whether it made sense or not.

(It mostly did.)

"....did it actually, or are you just saying that." 

"...yes...?"

What is the right answer!

"It's okay if it didn't." She keeps her voice a little gentler than she'd usually be. "Just, I'd like to know, because that tells me where my understanding might not be as complete as it seems from the inside." 

Wen Ning very quietly brings up one or two things he didn't understand.

As earnest a smile as she can physically produce.

"Thank you for telling me." 

Hm, what if she explains it this way instead, and instead of numbers she just has the shapes— 

He's helping make sure that Ayako understands things so it doesn't matter if he's very stupid.

He tries to repeat this to himself until he believes it.

The shapes are better but they still flip around in his head a lot.

Whenever he says out loud that he's confused by something, he gets the response, "Thank you, that's really helpful, let's try it a different way." What if they draw the shapes, so he doesn't have to hold them in his head? 

This is easier, he thinks.

It still takes him a lot of time to get it.

That's okay. They can't do this every day, she'll have other homework, but right now she's mostly interested in proving to Wen Ning and to his sister and frankly to herself that he can too learn things, if his teacher is patient. 

"Thank you," he says finally.

"You're welcome."