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Who is a knowledgeable person? Please help me with some math problems in Grade Three, ok? Urgent need! Thank you very much ?
I hope you can use it ~

1. A batch of bricks can be transported by two cars and three tractors in 32 times. If it is shipped by five cars and two tractors, it can be shipped in 16 times. Now it's 1 1 car transport. How many times can it be transported?

2. Use any three numbers in 1, 2, 3, 4, 5, 6, 7, 8 and 9 to make their sums different even numbers, so * * * has-different selection methods?

3. There is a string of numbers, the first one is 10, each number is 5 larger than the previous one, and the last one is 90. What is the sum of this string of numbers?

She is 72 years old and he 16 years old. A few years ago, she was eight times his age.

Answer:

1, 8 shipments.

From "two cars and three trailers can be transported 32 times", it can be transported 16 times with four cars and six trailers. 1 Compared with five cars and two tractors, the traffic volume of cars is equal to that of four tractors, which is easy to solve.

2. According to the knowledge of permutation and combination, there are two schemes to meet the meaning of the question.

1. Choose even number 3, that is, choose 3 from 2, 4, 6 and 8, and get four solutions: 12, 14, 16 and 18.

2. Choose even numbers of two cardinality numbers and get ten solutions of 681012141618 202224.

So * * * has ten plans.

Method 2: The sum of any three numbers in 1 to 9 is between 6 (minimum) and 24 (maximum), and there are 10 even numbers * * *, as above!

3、 850

Add up the first place, leaving 50 in the middle.

The age difference between them will never change, which is 72- 16 = 56 years old. When she is 8 times older than him, she is 8- 1 = 7 times older than him, and his 7 times is 56 years old. He should be 56 ÷ 7 = 8 years old. 16-8.

It's sticky below ~

1. Ten cases of flour, 20 bags each, 30kg each and 29kg each. How to find out the box of flour with different weight from the other nine boxes when it can only be weighed once?

Ten cases of flour from 1 to 10.

Take a bag from the bag 1.

Take two bags in the second bag.

Take three bags in the third bag.

……

10 package, take 10 package.

* * *1+2+3+...10 = 55 packages

Weigh these 55 packages, and then subtract this weight from the normal weight of 55 * 30 = 1650. Divide the difference by 30-29 = 1 and the number will be different. The difference of 1Kg is the first box, the difference of 2Kg is the second box, and so on.

2. Distribute pencils to 10 students. Each student has three pencils left, and each student has four pencils left, which is not enough. There are as many pencils left as there are not enough. How many pencils are there?

Distribution of pencils to 10 students. Each student needs 3× 10 = 30 pencils. Each student needs 4× 10 = 40 pencils. Because each student has three pencils, the remaining four are not enough, indicating that the total number of pencils should be more than 30 and less than 40. That is between 30 and 40. The total pencil difference between the two methods is 40-30 = 10 (branch) or (4-3) × 10 = 10 (branch). Because there are as many residual differences and insufficient differences between the two methods, each difference is regarded as 1.

Apply the law of quantitative relationship to calculate.

Problem solving: What is the total difference between the two scores?

(4-3) × 10 = 10 (branch)

How many copies is the difference between the two methods?

1+ 1 = 2 (copies)

How many branches are there in each division?

10 ÷ 2 = 5 (branch)

How many pencils are there?

30+5 = 35 (branch) or 40-5 = 35 (branch)

There are 35 pencils.

1, the library bought 200 new comic books, and the newly bought story books are five times as many as comic books. How many story books did you buy?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

2. A herdsman keeps 75 goats, and the number of sheep is three times that of goats. How many sheep does this herder keep?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

The store delivered 8 cases of soft drinks, each containing 24 bottles, and sold 96 bottles. How many bottles are left?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

4. The garment factory should produce 1450 pieces of children's clothes a week, 240 pieces a day in the first four days, and how many pieces should it produce in the last three days to complete the task?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

5. One bus can take 14 people, one bus can take 1 10 people, and four buses and eight buses can take * * how many people?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

6. Wang Jun and Liu Yun went swimming. Wang Jun swam 64 meters, Li Yun swam five times more than Wang Jun and swam 30 meters more. How many meters did Li Yun swim?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

7. The school held a celebration party. The students made 39 red flags, six more than the yellow flag, and the green flag was twice as big as the yellow flag. How many green flags are there?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

8. Ducks 15, 5 more than goslings, and the number of chickens is 4 times that of goslings.

(1) How many geese are there?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

(2) How many chickens are there?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

(2) How many chickens and goslings are there?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

9. Xiaohong reads a book. On the first day, she read 14 page. The next day, she read twice as many pages as the first day. There are 54 pages left. How many pages are there in this book?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

10, the school bought a batch of books and distributed them to five classes in Grade Three, with 52 books in each class. The remaining 156 books were distributed to senior two. How many books did the school buy back?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

1 1. There are 40 male students in the Lu primary school choir, and the female students are twice as many as the male students. How many girl students are there?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

12, Hong Guang primary school launched reading activities, and bought 240 books in grade two, twice as many as in grade three. How many books did you buy in grade three? How many books do you buy in two grades?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

13. There are 180 pear trees in the orchard. There are twice as many apple trees as pear trees, and three times as many apricot trees as apple trees. How many apricot trees are there?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

14. The price of four teddy bears is exactly the same as that of two pianos. It is understood that the price of a piano is 64 yuan. What is the price of a teddy bear?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

15. The students take part in the chorus. Boys stand in five lines, each line 12 people. There are twice as many boys as girls. How many girls are there?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

16. The number of monkeys in the zoo is only three times that of big monkeys. There are 96 big monkeys. How many little monkeys are there? How many big monkeys and little monkeys are there?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

17. The store sent 8 boxes of red ink, each containing 24 bottles and 205 bottles of blue ink. How many bottles of blue ink are there more than red ink?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

18, there are six green balls and 120 red balls. There are as many yellow balls as green ones. How many times are there red balls?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

19, the canteen bought 240 Jin of rice, ate 120 Jin, and ate the rest for 3 days. How many kilograms do you eat on average every day?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

The price of sweaters is 132 yuan, and the price of coats is three times that of sweaters.

How much is a sweater and coat?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

How much is a coat?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

C. How much is the coat more than the sweater?

A: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

Third grade application exercises (1)

Class name and student number

1. There are 4 boxes of pens, each containing 30 pens. How many pens are there in a box? If they are sold at 8 yuan each, how much can they be worth?

2. There are 3 flowers, each 16. How many bouquets are left after taking out 20 bouquets? 、

There are 4 bunches of flowers, each with 26 flowers. If you take out two flowers from each bunch, how many flowers are left?

Last year, 49 fish were raised, and the number of fish raised this year is twice that of last year. How many fish have you raised this year?

5. Xiao Min has 23 books, and Xiaoling's books are four times less than Xiao Min's, which is 15 less. How many books does Xiaoling have? How many copies do they have?

6. Xiaohua first collected 3 1 stamp and 14 stamp, which is exactly 5 times that of Xiaohong. How many stamps does Xiaohong have?

7. A car weighs 250 kilograms. How many cars of this kind weigh 1t?

8. How many kilograms is 200 kilograms of soybean oil per barrel and 5 barrels of soybean oil? How many tons?

9. One dress. 34 yuan, my mother wants to buy two pieces, and she needs 12 yuan. How much does her mother have?

10 4 classes, 28 people in each class participated in the skipping competition. There are 68 boys in the competition. How many girls are there?

1 1. There are 4 windows in each classroom, and 2 curtains are installed in each window. How many curtains should I install for 48 classes?

/kloc-there are 8 classes in Grade 0/2 and Grade 3, with 50 students in each class. Each person donated four books to the mountain school. How many books can a * * * donate?

13, 9 bags of rice were brought in from the grain store, each bag was 25 kilograms, and each kilogram was 3 yuan. How much can the rice be sold * * *?

14. Two cars of red bricks were delivered to the construction site, each with a price of 1200. The number of blue bricks brought is three times that of red bricks. How many pieces did you bring?

15. There are 48 peach trees. There are three times as many pear trees as peach trees, and twice as many apple trees. How many apple trees are there?

16. How many dm ribbons do you need to surround a rectangular photo frame with a length of 18dm and a width of 10dm?

17. Mom wants to sew lace with a length of 25 cm around the headrest. How many centimeters of lace does a * * * need? How many meters?

18. A wire is 100 cm long. Cut a section to make eight square frames with sides 2 cm long. How long is left?

19, there are 72 fish. If every three fish are packed in a plate, how many plates can you pack? If every four plates are packed, how many plates can you pack?

20. There are 96 students going boating. Each boat can take six people. Rent 9 yuan. How much does it cost to rent a boat?

2 1. The school bought 256 story books and 424 comic books, which were distributed to three grades on average. How many books are distributed in each grade?

22. The flower shop bought 167 lilies, and every 6 lilies were tied into 1 bouquet. How many bundles can they tie?

23. Students of grade three go to plant trees. There are 378 trees. There are 6 classes in each grade. How many trees should be planted in each class on average?

24. The students went on an autumn outing. 9 12 people were divided into three groups on average. Each group takes eight cars to visit. How many people are sitting in each car?

25. Xiao Liang was born in 1995. How old is he this year?

26. Xiaoli's home uses electricity 145 kwh every month. How many kilowatt hours did she use in the first half of the year? What about a whole year?

27. Xiaoming writes twice a day in July and August. How many strokes has he written in the past two months?

28. The bus stop sends five buses every two hours. According to this calculation, how many cars will be dispatched from 6 am to 6 pm?

29. An engineering team built 48 meters of road in three hours. At this rate, how many meters can be repaired in five hours?

30. Xiaoming bought 5 kilograms of apples and used 20 yuan. Xiaohong also bought eight apples. How much does she need?

1. An orchard is planted with 125 apple trees, and the number of pear trees is four times that of apple trees, with less than 20 trees. How many trees are planted in this orchard?

2. A section of road is 324 meters long, 240 meters has been repaired, and the rest is planned to be completed in 4 hours. How many meters are repaired per hour on average?

3. Hong Guang Printing Factory bound a batch of diaries, 960 copies were bound three days ago, and 420 copies were bound every day after 16. How many copies are there in this batch of diaries?

A typist enters 200 Chinese characters in 4 minutes. According to this calculation, how many minutes does it take to input 3000 Chinese characters?

5. Three bags of flour weigh 75 kilograms, and eight bags of flour weigh how many kilograms?

6. A steel plant needs 5 tons of water to smelt 750 kilograms of steel. According to this calculation, steel mills can save 55 tons of domestic water a day. How many kilograms can it make steel?

7. Five boxes of bees can brew 375 kilograms of honey a year. According to this calculation, how many Jin of honey can a 19 box of bees brew a year? How many boxes of bees does it take to brew 1725 kg of honey a year?

8. Two grade students go to buy books. There are 48 students in the third grade, each of whom bought two books, and each of them bought three books in the fourth grade. The total number of books bought in grade four is as much as that in grade three. How many people have bought books in the fourth grade?

9. Workers used 40 workers to build roads, but actually 45 workers were used. It was originally planned to build roads in 90 days, but how many days did it actually take?

10. It takes Xiaohua 20 minutes to walk home from school and 10 minutes to go home by bike. Xiaohua walks 45 meters every minute. How many meters does he ride a bike in each branch?

1 1. The school bought 15 boxes of colored chalk, each containing 50 pieces, and used 10 boxes. How many sticks are left useless?

12. The first, second and third workshops of Haitian Machinery Factory each produce 6 boxes of parts, each box 120 pieces. How many pieces did a * * * produce?

13. One loom weaves 2 1 m an hour. How many meters do four identical looms weave in five hours?

14. From Nanjing to Shanghai, the speed of the bus is 60 kilometers per hour, and it takes half the journey in three hours. Because one person in the car is ill, the rest of the journey will take two hours. How many kilometers per hour on average?

15. Master Liu processed 4255 parts in 23 days, Wang.

Master Liu processes 18 more parts every day on average. How many parts does Master Wang process every day?

16. A cow in Uncle Li's family eats 50 kg of grass 10 day. According to this calculation, how many days can this cow eat 155 kg of grass?

17. lakeside park cruise ship 18, daily income 1008 yuan. According to this calculation, there are now 26 cruise ships. How much will the daily income increase?

18. The factory has to process 360 parts, and Wang Can Jr. finished it in five days. How many parts can he process in eight days at this speed?

19. I read a story book, with 20 pages a day and half of it in five days. How many pages are there in this book?

20. The teacher bought six pens, which cost three times as much as ballpoint pens, and the price of ballpoint pens was 2 yuan. How much did the teacher spend on these pens?

2 1. A workshop of agricultural machinery factory is divided into three groups to process 3420 parts, with workers 12 in each group. How many parts does each worker process on average? (Solve in two ways)

22. The factory rents 10 vehicles to transport 480 tons of goods, and each vehicle transports 12 times. How many tons does each car transport at a time?

23. Woodpeckers can eat 645 pests a day, and frogs can eat 608 pests in 8 days. How many pests do woodpeckers eat more than frogs every day?

24. A pile of coal is 160 tons, and four trucks carry 96 tons three times. According to this calculation, how many times can four trucks transport this pile of coal?

1. Tianfeng Manor picked 82kg bananas, and 420kg bananas have been transported away. The rest are packed in a box every 32kg. How many boxes can you hold?

2. At the Red Scarf Holiday Activity Station, there are 98 people in the table tennis group, three times more than the basketball group. How many people are there in these two groups?

3. The canteen sent 82 Jin of potatoes, eggplant was 328 Jin more than potatoes, and eggplant was several times more than potatoes.

4. An engineering team has built a canal with a total length of1.450m, of which 640m has been built and the rest is still being built for 90m every day. How many days will it take to finish it?

The supermarket brought 248 cases of soybean oil and 388 cases of peanut oil. The total amount of soybean oil and peanut oil is 12 times that of salad oil. How many boxes of salad oil did you bring?

6. Distribute an average of 207 books to 23 reading groups. There are three people in each group. How many books were distributed to each person?

7. The waste battery recycling team collected 730 old batteries in three days, with an average of 240 batteries per day in the first two days. How many batteries were collected on the third day?

8. A manuscript is 24 pages, with 360 words per page, and Xiao Li types 72 words per minute. How long will it take to finish typing this manuscript?

9. A production workshop needs to process 4870 parts, of which 3 160 has been processed and the rest will be completed within 38 hours. How many parts are processed per hour on average?

10, Yucai Middle School Environmental Protection Team wants to plant 1450 pine trees, 580 trees have been planted, and the remaining 30 trees are planted in each row. How many rows can we plant?

1 1. Summer camp field marching training, A to B 2 14km, B to C 306km, 40km per day. How many days does it take to walk from A to C?

12, 24 cows produce 4656 kilograms of milk every day. How many kilograms does each cow produce on average?

13 and Li Shifu 1 hour can produce 52 parts. How many hours does it take to produce 364 parts?

14, Anshun transportation team used 26 vehicles to transport a batch of rice, with the first pile of 2,400 bags and the second pile of 3,528 bags. How many bags did each car carry on average?

15, the daily chemical company produced 4040 pieces of soap on the first day and 5770 pieces on the second day. If every 90 pieces are packed in a box, how many boxes can you pack?

19. An oil drum can hold 10 kg of oil. How many oil drums does it take to buy 650 kilograms of oil?

20. The distance from Hou Yaozong's home to the Botanical Garden is 1 792 meters, and the average walking time in Hou Yaozong is 28 meters per minute. How long does it take for Hou Yaozong to go to the Botanical Garden?

2 1. The height of a residential building15m, and the TV tower is 390m higher than the residential building. What is the height of the TV tower?

25. The construction team plans to pave a 90-meter road every day and finish it in 20 days. Actually, it only took 18 days. How many meters are paved on average every day? ,9,