Gu Xu was still very patient: "Little brother, let's continue to watch, on the first day, climb up and fall down again......

When the snail climbs to the 4th day, it climbs up on the 5th day......"

Gu Xu said as he took the eraser and climbed up to the back of the line he had drawn. If the snail climbs to the ground, it doesn't have to come down, so how much did it climb on the 5th day?

"9 decimeters." The little boy followed Gu Xu's train of thought and analyzed.

"That's right!" Gu Xu nodded, "Plus the 2 decimeters it climbed on the 1st, 2nd, 3rd, and 4th days, how many decimeters is in total?" ”

The little boy counted with his little hand: "2 plus 2 plus 2 plus 2, equals 8." ”

"Plus the ...... on the 5th day," Gu Xu continued to guide.

"8 plus 9 equals 17 decimeters." The little boy suddenly realized, and he sighed, "I know! ”

He was excited: "Thank you, brother! ”

Seeing that his son would know, his father was also very happy: "Oh, you have solved a big problem for me." ”

"You're welcome, uncle, you just have to pay, a dollar."

"It's only a dollar, so cheap!"

Gu Xu stalked: "Uncle, we have small profits but quick turnover." ”

"Son, don't you still have a lot of questions? Hurry up, let my brother teach you. The father couldn't wait to let Gu Xu teach him all the questions that his son couldn't do.

"Brother, there is this, this, here!"

Gu Xu suddenly couldn't cry or laugh, my God, how many of you can't do it!

He kept smiling: "It's okay, I'll teach you a way!" ”

Gu Xu taught the little boy more than 20 questions, both large and small.

"Anything else?" Gu Xu asked again.

The little boy flipped through the homework book and read it several times: "No! ”

He had a smile on his face: "Thank you, brother!" ”

Now it's okay, he doesn't have to be scolded by his dad anymore!

My father was very happy: "It's good, it's good!" ”

He sighed: "I finally don't have to worry about my son's homework." Every time I teach my son homework, I feel like I'm staring at my eyes and I can't stare for a long time. ”

Gu Xu said with a smile: "Uncle, I talked about a total of five big questions, ten medium questions, and eight small questions, a total of 63 yuan." ”

The father took out 100 yuan: "Don't look for it, I'm sorry for you today." ”

"Thank you, uncle!" Gu Xu said.

The father said and left happily with the little boy.

Lan Ruosi was very surprised: "He actually left without looking for money?" ”

Gu Xu calmed down: "Didn't you see that before he came, he was in an irritable mood?" We solved a big problem for him, and he was in a good mood to give more. ”

Lan Ruosi pursed her lips, and she immediately understood.

Gu Xu smiled: "This thing is not difficult!" ”

Lan Ruosi nodded.

"Or, next, you're coming?" Gu Xu was tempting.

"Ahh Lan Ruosi was shocked, and she shook her head.

She looked very simple, but she was still a little scared.

After a while, a middle-aged woman in her 40s with two children, the eldest was a boy who looked thirteen or fourteen years old, and the younger one was a girl who looked eight or nine years old.

Before Gu Xu could speak, the middle-aged woman said, "I heard that there is a young man here who specializes in tutoring homework, right?" ”

Gu Xu said politely: "Yes, is there something wrong with Auntie?" ”

"Hurry up, help them with their homework! I'm dying of sorrow. The middle-aged woman said as she asked the children to take out their homework books.

Gu Xu looked at Lan Ruosi: "Little porridge, look, there are two of them, otherwise, you will tutor one?" ”

Lan Ruosi hesitated and did not speak.

Gu Xu said again: "Look, it's not good to make people wait. ”

"Okay!" Lan Ruosi looked at the little girl, "Then I'll tutor this little girl!" ”

Lan Ruosi felt that the little girl should be more well-behaved and easier to teach.

Lan Ruosi said softly: "Little sister, where can't you?" ”

The little girl pointed to the question in the workbook: how to make four triangles with six matches.

Gu Xu looked at Lan Ruosiken's move, and he looked at the boy: "Little brother, where are you?" ”

The little boy also took out his workbook and pointed to the questions on it.

"Auntie, it's okay!" Lan Ruosi took the six matches brought by the little girl and finished them in a few seconds.

Gu Xu was unexpectedly surprised, he didn't even see the question, Lan Ruosi got it.

I'll go!

His little daughter-in-law has something in her head.

The middle-aged woman was shocked: "Little girl, you are really amazing." I used a toothpick at home to take this question, and I didn't succeed for several days.

The child has been arguing with me for a long time, and he will go to the tutorial class tomorrow, and if he can't answer, he will be ridiculed by his classmates.

I'm so sad that I don't know what to do!

You actually got it out in a matter of seconds.

This really solved my big trouble. ”

Lan Ruosi smiled: "Auntie, in fact, everyone will have a fixed thinking about this question, most people think about the plane, you just need to stand up." ”

Gu Xu was proud in his heart and proud of her: the little daughter-in-law is really amazing.

Later, I married her and had children.

When the child came to ask me how to do the question, I told him three words directly, find your mother!

Belch!

Looking for your mother, it doesn't seem right!

It should be, find your mother to teach you!

Gu Xu was shocked: Am I thinking a little far.

Actually, it's not far away, maybe it's there in the blink of an eye.

"Brother, how to do this question?" The little boy was very anxious when he saw his sister make it.

Gu Xu read out the question: "Grandpa's single-digit and ten-digit reversal of the number cube is a four-digit number, and the fourth power is a six-digit number, these two numbers just use the numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9, how old is grandpa?"

Gu Xu just finished reading, and the answer came casually: "81 years old!" ”

There were varying degrees of surprise on the faces of all those present.

Lan Ruosi was even more amazed: Gu Xu's computing ability is so strong.

The little boy blurted out: "Brother, you are so good, you will know the answer as soon as you finish reading the question." ”

"Because, when I read the question, my brain starts to calculate!"

The little boy looked dazed, and he felt like he was listening to a book from heaven.

Gu Xu smiled: "Actually, this question is very simple, and the key point is that you must first be familiar with the number of cubes in your mind."

The reversed number cube is a four-digit number, a cube of 10 is 1000, a cube of 21 is 9261, and a cube of 22 is 10648, which is a five-digit number.

The number after the reversal is between 10 and 21, so let's narrow it down.

Continuing to look at the following conditions, the fourth power is a six-digit number, and we can start with a slightly larger number.

The fourth power of 17 is 83521, the fourth power of 18 is the 104976 six digits, the fourth power of 19 is 130321, the fourth power of 20 is 160000, the fourth power of 21 is 194481, and the fourth power of 22 is 5153632, which is seven digits.

The range is narrowed again, between 18 and 21.

So, we have one last condition left, which is used from 0 to 9.

Grandpa's age is in the middle of the 18 to 21 numbers.

First of all, remove the most repeated 20, and then remove 19 and 21, and there are repeated numbers to the fourth power.

The answer is 18, and then it is 81. ”

Gu Xu finished speaking in one breath.

He looked at Lan Ruosi: This is thanks to his little daughter-in-law who embarrassed him just now.

I didn't expect it to be so coincidental.