Composition of Longgang 30 years ago 150

Today, my family went to KFC in Longgang for a family meal.

When we get there, people are always crowded. We finally ordered good food and found a seat to sit down. Here comes the food. This is a sumptuous set meal. There are 12 drumsticks in it. I thought: how to divide it equally? Then I remembered the division of 12÷3=4. We each have four drumsticks. Later, I ate my mother's 1 chicken leg and my aunt's two chicken legs. My aunt said, "You can't eat this for free. I ask you, how much did you eat? " How many more servings do you have to eat before you can finish them all? "I thought about it and replied," I ate 7/ 12, and then I ate 5/ 12. I ate all of it. "Fortunately, I learned the knowledge of fractions and can answer the questions correctly.

(2)

Today, my mother gave me 10 yuan to go shopping in the supermarket. I bought a string of firecrackers 2/ 10, four lollipops/10, seven balloons 2/ 10, and finally a comb 4/ 10, a *. There is still one yuan left, and I have to pay it back to my mother.

When I got home, my mother ate 1/4 lollipops, my father ate 1/4 lollipops, I ate 1/4 lollipops, and I gave the other one to my brother Xiao Qiang next door. (Author: Xiao Enling)

(3)

Last week, we studied fractions. Fractions have numerator, denominator and fractional line, for example, 1/3, where 3 is denominator, 1 is numerator and the middle horizontal line is fractional line.

Scores are used in many places in life. For example, a book has thirty pages, and each page is 1/30 of a book. Fractions can also be used to add and subtract! For example, half plus half equals two, which is 1. Why is this happening? If you divide a cake into two parts, each part is 1/2 of the cake, and then put the two parts together, there are two parts 1/2, which is just a cake. When adding and subtracting fractions, if the denominator is the same, only the numerator is added, regardless of the denominator. And 2/2 of the numerator and denominator are the same, which is 1.

I also learned to compare the size of fractions. The teacher taught us the formula: numerator is the same as denominator, the fraction with large denominator is small, and the fraction with small denominator is large; Denominators are the same as numerators, with large numerator scores larger and small numerator scores smaller.

The teacher also reminded us that when writing scores, we usually write the fractional line first, indicating the average score, then the denominator and finally the numerator.

4. Today, when I was reading Opening and Development, I found such a problem: a class of students participated in extracurricular activities. Boys account for 20% of the class, girls account for more than 2/7 of the class, and the number of people who don't participate is 5 less than 3/5 of the class. How many people are there in the class?

Because this problem has two definite quantities, I don't know how to start, but it is much simpler to use the equation:

Solution: Suppose there are X people in the class.

( 1-20%)X=(2/7X+2)+(3/5X-5)

0.8X=2/7X+3/5X+2-5

0.8X=3 1/35X+-3

28/35X-3 1/35X=-3

-3/35X=-3

X=3÷3/35

X=3×35/3

X=35

I once saw a deceptive trick in front of a supermarket.

There is a wooden disc. The pointer is fixed in the center of the disc with a nail. The disc can be rotated and divided into 24 equal cells, in which 1-24 equal numbers are written respectively. There is nothing valuable in the odd unit, but almost all even numbers are valuable.

The gameplay is also very simple. First set the pointer to 1, then you turn the disc, and the disc starts to rotate and finally stops. Then press the number marked on the grid where the pointer is located, and then dial the pointer to N- 1 grid (n is the number marked on the grid). In which box the pointer finally stops, the number in Gerry is yours.

I thought about it and found it impossible to get anything of value. Because when the pointer turns to an odd cell, the number of cells dialed is odd-1= even, and odd+even is only equal to odd, so it is impossible to turn to an even cell and nothing valuable can be obtained. If the pointer turns to an even grid and the number of grids dialed is even-1= odd, and odd+even = odd, then you won't get anything of value.

From this incident, I can see that some cheating methods adopted by some businesses must have been discovered by mathematics. So learning mathematics is very helpful to life, and mathematics is also needed in life.

References:

Multiple citation

Weigh shoes

There is a problem in today's math homework to weigh a pair of shoes. So I went to my mother and asked for a scale. Mom said she didn't have weighing scale. What shall we do? However, as the saying goes, "Nothing is difficult in the world". I think there must be a way.

So, I used my clever brain and came up with a homemade balance.

I cut off the paper covers of the empty moon cake box piece by piece, put on transparent tape, folded one of the paper covers into a regular triangle and put it on the table. Another piece of paper is made into the left and right disks of the balance and placed on the triangle in a balanced way. Then find something with weight at home as a weight. For example, my mother bought toothpaste, lipstick and other items, including 120g, 40g, 18g, 3g.

I'm very excited to say that the shoe activity has started. I put the shoes on the left side of the homemade balance and the "weight of goods" on the right side. It is best to balance the weight on both sides. Then the sum of the weights is the weight of my shoes. Exactly 86 grams. Hard work pays off! I finally finished my math homework. Mom praised me when she found out. Also jokingly said to me: "In ancient times, there was a clever Cao Chong as an elephant, and in modern times, there is a clever Hung Hung as a shoe!" " "Say that finish, everyone laughed.

It turns out that there are scales everywhere in life!

Thursday, September 29th, 2005 Weather: Sunny He Jiahong

Happy math class

In yesterday's math class, Teacher Yang told us about "going to the playground". Because this is an interesting project, the students are very active in asking questions. I am no exception. After thinking about it, I raised my hand and asked such a question: "Is 200 yuan enough for 16 people to finish three projects?" Teacher Yang praised me for asking a particularly difficult question. However, at the prompt of Teacher Yang, I also helped my classmates to answer the questions. I remember a scientist said, "It is often more difficult to ask a question than to solve it." In this math class, we not only raised many questions, but also solved many problems. How amazing we are!

Weather on Sunday, June 2, 2005 +65438: Sunny He Jiahong

I'm great.

Today, we go to Happy Valley to play. The adult entrance ticket price of Happy Valley is: 140 yuan; Half a ticket for children. While waiting in line to buy tickets, my mother asked me to calculate how many tickets we need to buy. I blurted out, "I want 700 yuan." My mother asked me in surprise how I calculated so fast. Actually, I think so: four half-price tickets for children are equal to two adult tickets, plus three adult tickets are exactly five adult tickets, and five tickets for 140 are exactly equal to 700 yuan. Mom praised me for being great!

Thursday, June 65438, 2005+10/October 65438+March weather: sunny and sunny.

How many times does Shenzhou VI circle the earth every day?

Today, when the director of Beijing Aerospace Control Center told the reporter interviewed, "It takes 90 minutes for Shenzhou VI to orbit the earth once." After listening to it, I thought, "So how many times can Shenzhou VI circle the earth in one day? So I quickly calculated with my brain: there are 24 hours in a day, 1 hour is 60 minutes, that is, 24 times 60 is a day 1440 minutes. Then divide 1440 minutes by 90, which is equal to 16 laps. Also, Shenzhou VI will explore in space for five days, that is, 80 times around the earth. Astronauts are really amazing!

20051October 20th (Thursday) Weather: Sunny He Jiahong

Count soybeans

Today's math class is a practical activity. We were divided into groups of eight people. Then the members of each group work together to figure out how many soybeans there are in 1 kg. According to the estimation method introduced in the book, it seems not difficult, but it is necessary to be careful to minimize the error.

I originally suggested that our group would use more cups accurately. But I can't find the cup. Later, this group of people chose the method of grasping by hand. Team member Luo Guangyuan is responsible for catching. Oh, dear! Luo Guangyuan's little hands are quite big! One catch is 180 grains, and 30 consecutive catches have just finished 1 kg of soybeans. Finally finished. 30 180 equals 5400 capsules. So I know there are about 5400 1 thousand soybeans.

This practical activity inspired me. I might as well try melon seeds, candy and peanuts. In fact, math problems are closely related to life.

Defendant: Degeneration-Assistant II 2009-2-6 00: 16

It will be cloudy on Wednesday, March 23rd.

Today, after I signed up for school and went home, I wrapped the book cover and began to calculate the cost of this semester.

The first is tuition. Tuition fee is 4 10 yuan, plus drinking water fee in 20 yuan, 430 yuan. Next, the charge of the Olympic Mathematics School is 180 yuan. It is estimated that the bus fare is in 20 yuan and ***200 yuan. There is also money to buy exercise books: 2 copies of "Classpass" 2 1.5 yuan; English practice 1 9.9 yuan; 2 copies of Examination Paper Course Pass 15.9 yuan; "Jiangsu Big Test Paper" 3 copies 2 1 yuan. 21.5+9.9+15.9+13+21= 81.3 (yuan).

Study fee: 430+200+81.3 = 711.3 (Yuan).

Living expenses: I will drink about 5 cases of milk this semester, 5×30= 150 yuan. Every meal is about 2~3 yuan, of which 2.5 yuan is 2.5×3×30×5= 1 125 (yuan). "What else?" I bit my pencil and said to myself, "and your school supplies." Hey, mom's home. Yes, and school supplies.

School supplies: a pencil-box 8 yuan, a pencil-box 3 yuan (very cheap, clearance goods), six pencils 3 yuan, an eraser 0.5 yuan, two triangular rulers 1 yuan, two mechanical pencil 5 yuan, 8+3+0.5+ 1+5=20.5 (yuan).

Total expenditure: 711.3+150+1125+20.5 = 2006.8 (yuan).

Wow, I didn't expect that I, who usually don't spend much money, would let my parents spend 2006.8 yuan this semester. It seems that I will save money!