When did this woman become so understanding?

Never mind, he can't stand for too long. He should finish his homework and go back to lie down.

After Yi Shuihan finished reciting the texts from the past few days, Xiao Qingyin practiced her spoken English with him for a short while.

"Excellent!"

Xiao Qingyin praised him highly.

"Thanks."

Yi Shuihan smiled modestly.

"Alright, you should go back now."

Xiao Qingyin felt that his face was getting paler and paler.

Yi Shuihan hesitated, wanting to speak but stopping himself.

"Is there anything else?"

"The Crown Prince left people to escort you today. I learned about the uses of calculus from them. The development of artillery has just hit a bottleneck. I would like to ask if you have any textbooks on calculus here?"

Yi Shuihan asked.

Xiao Qingyin: "..."

Where did you find such a motivated, studious, and obedient beauty?

She really wanted to pick one up too.

"Yes, we do have some," Xiao Qingyin replied, "but it's the same price as an English textbook. Will you buy it?"

Yi Shuihan had already guessed what price she would ask for.

"I'll buy it, but I don't have the money right now, and neither does the young master. Can we pay you when the glass workshop makes money?"

"Tsk tsk."

Xiao Qingyin raised an eyebrow.

"You're trying to get something for nothing."

She provided the glass manufacturing formula, and before the product was even finished, he used the profits to buy textbooks on credit.

She would be the first to get angry if anyone said that the heir of the Marquis of Yong'an was a boor.

Yi Shuihan's ear tips turned slightly red.

I felt a little guilty.

But he was short of money; he couldn't even come up with a thousand taels, let alone ten thousand.

"No problem, I can give it to you on credit."

Xiao Qingyin said generously.

"Do you only need mathematical calculations? Do you also need chemistry, physics, biology, or anything like that?"

Yi Shuihan was greatly shocked.