Imelda looks dubious. 

"You can use science to work out how fast something will fall,  and be able to predict it every time.  Or work out how likely someone is to catch a disease, and how likely you are to cure it." He is saying this for Imelda, yes, but he is also saying it for his students.

"I don't know what that means! How do you make catching diseases into a math problem? Either they have it or they don't."

"Sure, you either have it or you don't, but you're more likely to catch some diseases, and some people are more likely to catch some diseases and others. And if you there are two disease that look similar that someone could have, that math can be very helpful." He will wait until the child is more numerate to explain the hell that is medical test probabilities.

"I think this math is more interesting than the other math. Because it is about diseases."

"Magic is math too," Minelia says. 

"And you may be able to work out how to combine them." Gotta make sure the students aren't worn down to demotivated nubs too early.

"Is there much topology in medicine?"

"Unfortunately, no."

Oh no was that a stupid question. It was a stupid question, wasn't it. 

"I think I should learn the medicine math and not the other math. I don't need to know how things fall down."

"Unfortunately, you also need to know the other math to get to the medicine math," he says in the same tone he'd say 'Unfortunately, you need to eat your vegetables.'

"What is the medicine math? We might have already developed it," says Minelia, who is planning to claim that she's never heard of that kind of math, bribe and threaten someone into getting her a relevant math textbook, study ahead, and show off as soon as they get there. 

"A lot of statistics and probability. Some logarithms and such like once we get to biochemical pathways."

"We weren't taught that in wizard school," Minelia says truthfully. 

"Don't worry, we'll cover it."

Minelia is going to make her excuses and set off to threaten someone into getting her a textbook. 

As she leaves, Imelda comments, "I don't think she likes learning."

Ah, small children. "That's not a very nice thing to say."

"It's true! It's always okay to say true things."

"You've still got to think about what someone would think if they overheard you."

"Well, then we can go in a corner and I can say true things."

He needs to impart a moral lesson to this child and not start laughing. "How would you feel if you found out other people were talking in corners about you?"

"Well, are they saying true things about me or false things?"