But it seems there's nothing there. After she finished writing, she checked it herself to make sure there were no problems, and then folded the two pieces of paper together.

Gao Kangcheng softened his expression and quickly said, "That's right, no mistake, all the answers to this question are correct. I just wanted to ask about the solution process, because..."

As he spoke, his expression became awkward; a man in his forties asking a young woman in her twenties such a question.

"No problem, let's sit down and talk." Lin Yuxi suddenly realized and nodded.

These kinds of questions, which are typical of later generations, didn't exist at this time, so it's normal that he couldn't understand them.

Gao Kangcheng quickly pulled out a chair for Lin Yuxi and then handed her paper and a pen.

"Which problem's solution don't you understand?" Lin Yuxi asked, looking at the answers above.

"I don't understand any of them."

Hearing Gao Kangcheng's embarrassed reply, Lin Yuxi nodded.

Lin Yuxi took his paper and pen and carefully wrote down each item.

"Does this answer require no draft or abacus? How did you calculate it so directly?" Gao Kangcheng stared wide-eyed, his face filled with shock.

Lin Yuxi replied, "I don't need to, I'll do it mentally."

If he hadn't verified it last night, he would have thought Lin Yuxi was bragging. He quickly said, "You can do mental arithmetic?"

Actually, mental arithmetic is already possible at this point. Very few people can do mental arithmetic with such complex data; it takes time to calculate everything carefully.

"Hmm." Lin Yuxi nodded. "If you practice more, it will be easier to learn later."

She didn't waste time on mental arithmetic and continued explaining the problem to Gao Kangcheng. Seeing that it was almost time, she stood up and said, "You can continue studying. I'm going to find a book. I'll head back soon."

"Then... then will you come tomorrow, young lady?" Gao Kangcheng asked awkwardly.

Lin Yuxi shook her head. "Whether you come or not depends on your mood. I mainly came to borrow books today."

After all, she felt that coming every day was quite tiring, like clocking in and out of get off work, so it was more convenient to borrow books to read at home.

I'm not coming!

Gao Kangcheng wasn't planning on getting something for nothing. "Actually, I wanted to ask if you could help me solve some other problems. Don't worry, I definitely won't let you do your work for free. Sixty yuan, how about it? It's okay if the answer is wrong, we'll calculate it carefully later."

He carried those things with him at all times, and he immediately took them out to show Lin Yuxi.

Lin Yuxi glanced at it.

"OK."

How often do you need it?

Gao Kangcheng was dumbfounded. Was she planning to do it right here?

"I'll write down the answer for you now." Lin Yuxi picked up a pen and started writing on the notebook. She had originally planned to stay in the library for half an hour, but she had already spent half an hour explaining to Gao Kangcheng. Writing these pages would take about an hour and a half.

After finishing all that, she unscrewed the kettle and took a sip of water. The honey water moistened her mouth. She then lowered her head and raised her hand to write on the paper.

Gao Kangcheng was so nervous he didn't dare blink. As the other person gradually sped up, his mental calculations couldn't keep up, and Lin Yuxi was already working on the next problem.

"I'm done writing. I'm going home for dinner. Here's the answer key. You can take it." Lin Yuxi handed him the document, and Gao Kangcheng kept his word, taking out five ten-yuan bills.