Teaching the Little Terror a Lesson!

Qi Hao nodded, pretending not to notice the hand she had withdrawn.

Fang Jiaze, who was sprawled crookedly in the gaming chair beside her, was amused. He whistled. "Whoa, another one here to give me experience points. Bro, you're only a freshman, right? You look even less like a teacher than my sister. Can you actually do this?"

Qi Hao ignored Fang Jiaze's provocation and asked directly, "Do you like playing games?"

Fang Jiaze was taken aback. Clearly, he hadn't expected the new tutor to ask whether he played games instead of asking about his grades or opening a textbook.

"Why are you asking?" Fang Jiaze watched him warily, as if trying to judge whether the young tutor was about to pull some old educational-entertainment trick on him.

His dad had hired several people to tutor him before. One had even offered candy as a reward, as if coaxing a kindergartener, and Fang Jiaze had driven him away with his retorts.

Qi Hao didn't answer directly. He glanced around the study.

A seventh-grade math textbook lay open on the desk, turned to the chapter on rational numbers. Beside it was a workbook that had barely been touched. The BenQ LCD monitor on the desk stood out in particular. The computer tower was covered in game stickers, and a headset lay on the desktop.

Qi Hao had a rough idea of the situation.

In this era, computer games had swept through every street and alley. What boy wasn't hooked?

A boy who had just started seventh grade, equipped with a computer like this-it was only normal that he didn't like studying.

It also showed that Fang Guoping really did spoil his youngest son.

If he could handle this kid, his tutoring job would be secure.

"I'm asking whether you play games because, if you do, math won't be hard for you." Qi Hao pulled over a chair and sat down naturally, without a trace of a new tutor's awkwardness.

Fang Jiaze's interest was piqued, and he sat a little straighter in his gaming chair. "What do you mean?"

Fang Jiaxue stood to the side without speaking.

Her brother had nearly driven her mad just now, and she was eager to see what the new tutor could do.

Honestly, her first impression of Qi Hao hadn't been particularly good. Though he was reasonably good-looking, he was almost the same age as her. How professional could he be?

"What games do you play?" Qi Hao continued.

"CF." Fang Jiaze couldn't hide the pride in his voice. "I'm in the top hundred on my regional server in the Hundred Cities League. You know what that means?"

"CrossFire?" Qi Hao nodded. "Then let me ask you this: you bought a hero-tier weapon in the game for 888 Q Coins, and then Penguin ran a promotion for 30 percent off. How much would you save?"

"621.6. Save 266.4." Fang Jiaze practically blurted it out without even thinking.

Qi Hao asked again, "You have 3,000 Q Coins on your account. You top up 648, then another 328, and spend 888 on a gun. How much is left?"

"3,000 plus 648 plus 328 minus 888... 3,088."

Qi Hao turned to Fang Jiaxue and smiled. "See? He doesn't hate math. He just thinks the stuff in the textbook has nothing to do with him."

Fang Jiaxue was slightly stunned.

She had never looked at the problem from that angle.

As she saw it, her brother was willful and mischievous. He simply didn't like studying and was too fond of playing, so he needed to be forced to study. Yet with just a few words, this new tutor had gotten the little terror to sit quietly and work out two problems. They were simple, but it was already a remarkable start.

Fang Jiaze was stunned for a moment too, but then he dismissed it. "How is that the same? Q Coins are money. What use is the stuff in the math textbook, like rational numbers, negative numbers, and absolute values?"

That was exactly what Qi Hao had been waiting for him to say.

He picked up a pen from the desk, took a sheet of scratch paper, and drew a horizontal line, marking zero in the middle. Then he said to Fang Jiaze, "When you play CF, you know Mutation Mode, right?"

"Of course. I'm MVP every match in Mutation Mode."

"All right, you're in the middle of the map now. Ten steps forward is the safe house, and five steps backward is the poison zone. Forward is the positive direction, backward is the negative direction, and where you're standing is the origin, zero." As Qi Hao spoke, he marked the numbers on the line.

"If you go ten steps forward, your position is positive ten. If you go five steps backward, your position is negative five. This line is a number line."

Fang Jiaze blinked. This was probably the first time in his life that the words "number line" had seemed less loathsome.

"Then what about absolute value?" Fang Jiaze asked instinctively. As soon as he did, even he was taken aback. When had he started asking math questions on his own?

The corners of Qi Hao's mouth lifted slightly. As casually as if he were chatting with a friend, he said, "Absolute value is even simpler. Whether you go ten steps forward or five steps backward, your distance from the origin is always positive, right?"

"You can't say you're negative five steps away from the origin, can you? Distance can't be negative, so the absolute value of positive ten is ten, and the absolute value of negative five is five. You just remove the negative sign and look at the distance."

He added, "It's like playing CF. Whether you get headshot or you headshot someone else, when your kills and deaths are tallied at the end, the KD ratio looks at the absolute numbers. If you died five times, you can't say you were alive negative five times, can you?"

"Hahaha!" Fang Jiaze laughed despite himself. "Alive negative five times? Wouldn't that just mean you died five times? You'd be a ghost!"

"Right. So absolute value is distance without direction, and it's always nonnegative. See? What's so hard about that?"

Fang Jiaze looked down at the problem in the textbook that had been driving him crazy, and suddenly it didn't seem quite so hateful.

"Five minus negative three... equals five plus three, which equals eight?" Fang Jiaze ventured.

"See? You know how to do it, don't you?" There was no exaggerated praise in Qi Hao's voice, just matter-of-fact affirmation, as though it were perfectly natural for Fang Jiaze to be able to solve the problem.

"The distance between two points is the larger number minus the smaller one, or you can add their absolute values together, provided one is positive and the other is negative. The method you just used was completely correct. Five minus negative three: subtracting a negative number is the same as adding its absolute value, so it's eight."

Fang Jiaze picked up his pen and wrote the answer in the workbook.

It was the first problem he had done that day.

Qi Hao didn't stop there. A little spark of interest like this could go out as quickly as it appeared. If he didn't strike while the iron was hot, he would have to break the ice all over again next time.

"Here's another one." Qi Hao wrote a problem on the paper as he spoke. "You're playing someone one-on-one in CF. If you win, they give you 100 yuan; if you lose, you give them 50 yuan. You play six rounds, win two and lose four. Did you end up making or losing money? How much did you lose?"

Fang Jiaze looked down and calculated. "Winning two rounds is positive 200, losing four is negative 200, so together that's zero... No, wait." He scratched his head. "Winning two rounds is plus 200, losing four is minus 200. Two hundred minus 200 is zero? I played six rounds for nothing?"

"Calculate it again."

Fang Jiaze carefully worked it out again. "Winning one round is plus 100, so winning two is positive 100 times two, which is positive 200. Losing one round is minus 50, so losing four is negative 50 times four, which is negative 200. Two hundred plus negative 200... is zero."

He looked up at Qi Hao. "It really is zero? Six rounds for nothing?"

Qi Hao nodded. "Right. That's mixed arithmetic with rational numbers. See? A positive number times a positive number gives you a positive number, and a negative number times a positive number gives you a negative number. Finally, add the positive and negative numbers together. You've been using this thing you thought was so difficult all along; the textbook just packaged it so you didn't recognize it."

"If you learn math well, even playing games will be a lot easier."

"Otherwise, you'll be a walking leek in the game someday."

Fang Jiaze fell silent for a few seconds, then said something even he couldn't believe. "Um... could you explain the next problem, the one about multiplying rational numbers?"

Fang Jiaxue stared at her brother in disbelief.

Her brother, Fang Jiaze-the so-called math insulator who had made four tutors resign one after another-was actually asking someone to explain a problem?

Qi Hao breathed a sigh of relief inwardly, but showed nothing on his face.

Fang Jiaze's foundation actually wasn't bad. He was quick to react and good at arithmetic. The problem lay in his attitude toward studying and his interest in it.

As long as he found what interested him and translated those mathematical concepts into language he could understand, it wouldn't be hard to bring the boy's grades up.

Over the time that followed, Qi Hao repackaged all the key concepts in the rational numbers chapter as gaming scenarios.

He explained negative numbers using CF's economy system: money spent buying guns was negative, kill rewards were positive, and the end-of-round tally was positive and negative numbers added together. For the sign rules of multiplication, he used "the enemy of my enemy is my friend" as an analogy for two negatives making a positive. For division, he simply had Fang Jiaze calculate his match KD.

Before he knew it, Fang Jiaze had done twelve problems in one sitting.

The last time he had done that many problems in one sitting was back in fourth grade, when his sister had locked him in a room and refused to feed him until he finished.

"All right, that's it for today." Qi Hao closed the workbook, stood up, and stretched.

"Huh? It's over already?" Fang Jiaze actually looked like he wanted more, but he immediately realized his reaction wasn't quite right. He hurriedly cleared his throat and put his carefree manner back on. "I mean... it's finally over. I'm exhausted."

Qi Hao pretended not to notice and smiled. "Before I come next time, do pages fifteen through twenty in the workbook. Leave the ones you can't do blank for now, and I'll explain them when I come."

"Tch, I'll see."

Qi Hao turned and headed for the door. Fang Jiaxue had already gone out ahead of him and was waiting in the hallway.

The lights in the second-floor hallway were a warm yellow, and they fell on Fang Jiaxue's face, making her look much softer than she had in the study, where she had looked fierce enough to thrash her brother.

"You..." Fang Jiaxue hesitated, seemingly trying to find the right words. In the end, she only said, "Have you tutored anyone before?"

"To tell you the truth, no. Your brother is actually quite smart. He just needs someone to communicate with him in a special way, and I happened to get it right."

Qi Hao spoke honestly, without inventing any tutoring experience for himself.

"What school do you go to?" Fang Jiaxue asked.

"The Open University, math department."

"Math department? That's the same as my best friend. She's been taking part in math competitions lately. Have you entered any? Will tutoring Xiao Ze interfere with them?" Fang Jiaxue asked worriedly.

"I haven't entered any competitions, so don't worry about my schedule. There won't be a conflict."

Qi Hao thought, At 300 yuan an hour, this tutoring job is my biggest source of income right now. Forget a scheduling conflict-even if there were mountains of blades and seas of fire ahead, I'd still show up at the Fang Household's door on time!