Math problems good plus 40 should be columnar

1. The two are as shrewd.

50% sold, and there are still 100 cartons of milk left:

Yingying's practice can be sold: 100 (4+1)=20, 40*20*4=3200 (yuan).

Nini's approach can be sold *100=3200 (yuan)2, with a more stupid method is to add one by one:

24 + 25 + 26 + 27 + 28 + 29 + 30 + 31 + 32 + 33 + 34 + 35 + 36 = 390 (person).

Calculations can be summed using a formula for a series of equal differences, or using a calculator.

3. If the original science and technology books are x, then there are (1050-x) literary and art books.

x+56）/(1050-x) = 4/3

Solution x=576

Therefore, the original science and technology books are 576.

4. If a total of x boxes of apples are shipped, then:

x-(1 3)x-45=45+(1 3)x, the solution yields x=270

A total of 270 boxes of apples arrived.

1.Solution: Ying Ying is shrewd because she sells milk quickly in her way.

2.Solution: [24+36)*(36-24+1)] 2=390 (person) 3Solution: If there are x original science and technology books, then there are (1050-x) literature and art books.

x+56):(1050-x)=4:3 Solve the equation to obtain: x=576 (Ben)4Solution: Set a total of x boxes of apples shipped, and the title has the following meanings:

x-45-1 3 x= x 2 solution: x=270 (box).

Question 1. The remaining milk is 100 cartons.

According to the method of Yingying, that is, 5 cartons of milk are 40 * 4 = 160 yuan, with an average of 32 yuan per box.

According to Nini's method, the 20% discount is 40* yuan.

The price is the same, so it's just as smart.

Question 2. Since there is one more seat in the front row than in the back row, the number of seats at a time is 24, 25, 26 ......34,35,36

Add these numbers to get (24 + 36) * 13 2 = 390 seats.

Question 3. If there are x science and technology books, then 1050-x literary and artistic books.

According to the equation (x+56) (1050-x)=4 3, x=576 is solved

Question 4. A total of x boxes of apples were shipped.

x-45-x/3=x/2

The solution is x=270

1. There is ambiguity in this question.

If Yingying's request is to either not buy it, or to buy it, you have to buy four boxes, then Yingying is as shrewd as Nini. Because selling these 100 cartons of milk, Yingying made a total profit of 40 4 (100 5) 100 32=0 and Nini made a total profit of (40, so the profit is the same.

However, if Yingying's requirement is to buy enough 4 boxes and give 1 box, if there are less than 4 boxes, it will not be given away (this understanding is more in line with reality). Then, because not everyone will buy four boxes at a time, Yingying's business mode can earn at least 0 yuan, that is, everyone will buy 4 boxes; You can earn up to (40 32) 100=800. And Nini's profit is still not 0 yuan, so Yingying is more shrewd.

2. I don't know what age the landlord is, so there are two solutions.

2) Sum of the difference series, the first term is 24, the last term is 36, a total of 13 terms.

So (24 36) 13 2=390

158 4-56=576 (books) It turns out that there are 576 science and technology books.

4. If you know the equation, set a total of x boxes.

45 (1 3)x=(1 2)x solution x=270Note: No, don't mislead people's children!!

1.Nini is more savvy. There are 100 boxes left, Yingying "buy four get one free" can be sold to 20 people, 4 * 40 = 160 yuan people, an average of 32 yuan boxes, income 3200 yuan, Nini "80% off" 40 * yuan box, income 3200 yuan, for customers are 32 yuan boxes, will definitely buy one box by one, and milk is easy to spoil products.

2.This is a series of equal differences, a1=24,d=1,an=36an=a1+(n-1)d=24+(n-1)*1=36, which gives n=13, that is, there are 13 rows of seats.

Total number of seats SN = 13 (24 + 36) 2 = 390 seats.

3.Set up the original science and technology books x books, literature and art books (1050-x).

x+56）/(1050-x)=4/3

Solve the equation to get x = 576 copies.

4.A total of x boxes of apples were shipped.

The number of cases sold is 45+(1 3)x

The number of boxes left is x-[45+(1 3)x].

So there are 45+(1 3)x=x-[45+(1 3)x] to solve the equation to get x=270 boxes.

Yingying's buy four get one free and Nini's 20% off**are both in the form of not making money**, so they are just as shrewd.

The number of rows is 36-24+1=13, rows 13*(24+36) 2=390

1.Greet the shrewdness.

Yingying: If the remaining 100 boxes are all sold in a buy four get one free, the income.

4 * 40 * 100 5 = 3200, if it is not sold in the way of buy four get one free, the income must be greater than 3200 yuan.

Nini: 40*100*80%=3200, that is, the income is 3200 yuan.

Therefore: welcome and be shrewd.

2。There are a total of 36-24+1=13 rows in this classroom, so you can sit in total:

36 + 24) * 13 2 = 390 people (Gauss sum) 3. (1050+56)*4 (4+3)-56=576 copies. Box.

1.The attendance rate of a certain field today is 98, 3 people are on sick leave, 1 person is on personal leave, and this factory has "196" people on attendance today.

2.There are 20 kilograms of mushrooms, his water content is 99, the water content is reduced to 98 after a little cooling, and the mushrooms after drying weigh "10" kilograms. 20* (1-99%) answered (1-98%)

3.The accuracy rate of a shooting training was 99, of which 6 misses, and this shooting training had a "594" hit.

4.The subtraction, the sum of the subtraction and the difference is, the known subtraction is the difference of 80, the subtraction is ", the subtraction is ", and the difference is 3

Subtracted = Difference = Subtraction =

1. To pack a batch of "Shenzhen Special Zone Education" magazines and send them to the post office (the same number of copies in each package), this batch of magazines is 3 5 enough to play 5 packs and 44 more, if this batch of magazines can just play 9 packs, then how many copies of this batch of magazines are there? (Ask for a column equation solution).

x/9=(3x/5-44)/5 x=990

2. The surface area of 34 square centimeters, 96 square centimeters, and 150 square centimeters of three iron cubes is refined into a large cube (excluding loss), and the surface area of this large cube is found.

3 3 + [ 150 6)] 3} 2 * 6 = 216 square centimeters.

3. The profit margin of a commodity is 20%. If the purchase price is reduced by 20% and the sell price remains the same, how much will the profit margin increase? (Profit = Selling Price - Purchase Price, Profit Margin = Profit Purchase Price x 100%.)

1. Set each pack of x copies, then the total number is 9x, 3 5 * 9x = 5x + 44, the solution is x = 110, and the magazine has a total of 9x = 990 copies.

2. The edge length of the three cubes is the sum of the volumes of the three cubes: 3 3 + 4 3 + 5 3 = 216, and the edge length of the large cube is the cubic root 6 of 216

The surface area of a large cube = 6 6 2 = 216 square centimeters.

3. When the purchase price is 1, the selling price (1+20%), the purchase price is reduced to (1-20%), profit: (1+20%)-1-20%) = 40%, and the profit margin = 40% (1-20%) =, that is, the profit margin is increased to 50%, which is increased by 30%.

1.There are x magazines and each pack of Y books. Then:

3/5 x=5y+44 9y=x

Solution: x=990 y=110 So this batch of magazines is 990 copies 2From the inscription, the three cubes become 3, 4, and 5 respectively, and the surface area of the large cube is set to x square centimeters, then.

x 6) cube = 3 cube + 4 cube + 5 cube x = 216 square centimeters.

3.If the purchase price is x, then the selling price, and if the profit margin increases y, then.

20%+y=【 x=20%

20% 20% = 100% so the profit margin increases by 100%.

1. If there are x copies of the magazine, then (3 5 x-44) 5=x 9 x=990

6=9, then the side length is 3cm

96 6 = 16, then the side length is 4cm

150 6 = 25, then the side length is 5cm

3 3 3 + 4 4 4 + 5 5 5 = 216 cubic centimeters 3, let the selling price be x, the purchase price is y, then (x-y) y = 20%, x = the current purchase price is, then (, increased by 30%.

The question is not all three. 12000 multiplied by a third equals 4000. 4,000 times three-and-half equals 6000 Question 1: If the scale is 1:2000, the actual length is 7000cm, which is 70m, and the width is.

When the purchase price is 1, the selling price (1+20%), the purchase price is reduced to (1-20%), the profit: (1+20%)-1-20%)=40%, the profit margin = 40% (1-20%)=, the profit margin is increased to 50%, so it is increased by 30%.

Question 2: Let the side length be a 6a square 54 a 3 In the same way, the side length of the other two is 4 and 5, and the total volume is 3 cubes plus 4 cubes plus 5 cubes 216 So the volume of the large cube is 216 So the side length of the large cube is 6 So the surface area is equal to the square of 6*6 216

It should be taught to the child, first of all, you have to tell him the conversion of the unit: 1 kg = 1000 grams, 1 ton = 1000 kg, and the problem that bothers the child should be 1.6 million and the conversion of the unit. You can do this to see.

First tell him that 1.6 million is 1600000, and it can be said that 10,000 means that it is followed by 4 0s, so that the explanation is easy for the child to accept, and he will have his own way of understanding when he is exposed to more contact in the future.

Take paper saving as an example: 1.6 million students save 1,600,000 2=3,200,000 (grams) by saving one per person

Then convert grams to kilograms, divide the above results by 1000, which is a saving of 3200 (kilograms), and then divide by 1000 to convert into tons as a unit is tons. According to the pattern of finding a model, the last two questions can be done by the child himself, depending on the child's acceptance and understanding of the above process.

1: Saving paper: 1600000 2 1000 1000=tons;

2: Coal saving: 1,600,000 tons;

3: Reduce carbon dioxide emissions: 1,600,000 tons.

Note: The first 1000 is 1 kg = 1 kg, and the second 1000 is 1 thousand kg = 1 ton.

1 ton is 1000 kilograms, and 1 kilogram is 1000 grams.

According to the title, if each person saves one piece of paper, the number of papers saved is: 1.6 million grams of paper saved is:

1600000*2=3200000 grams.

Convert to tons to tons.

The number of grams of coal saved is:

1600000* grams.

Convert to tons to tons.

The number of grams that reduce CO2 emissions is:

1600000* grams.

Convert to tons to tons.

Write 1,600,000 as 1,600,000, and the rest is simpler.

2 1600 = 3200 kg = ton paper ton kg = ton coal ton.

Kilogram = ton Tons of emissions reduced.

1 ton 1000 kg 1000000 grams.

Saving paper: 1600000 2 1000000 = tons of saving coal: tons.

Less carbon dioxide emissions: tons.

2*1,600,000 = 3,200,000 grams = tons (paper).

tonnes (coal) tonnes (carbon dioxide).

It was observed that the sequence is 6 cycles 2, 5, 2, 2, 6, 8, and 25

994 6 = 165 remainder 4, so the remainder 2,5,2,2, and sum are 11

So the sum is 25*165+11=4136

2,5,2,2,6,8,2,5,2,2,6,8,2,5……Every six numbers in this column is a cycle, and 994 165*6+4

So the sum of the first 994 numbers in this column is.

1、（26-8）÷26=18/26≈

2, (104-80) 80 = 24 80 = 30% 3, wrong, Dong Dong is 20 higher than Xiao Hong, then Dong Dong is 120% of Xiao Hong's height, that is, Dong Dong Xiao Hong 6 5

Then Xiaohong is Dongdong height 5 6, and Xiaohong is 1 6 less than Dongdong, that is, less.