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300 problems of mixed operation of addition, subtraction, multiplication and division in the fifth grade of primary school (part one)
1, a canal is ***6400 meters, and it will be repaired 1200 meters per month on average in the first three months, and the rest will be completed in two months. How many meters will it be completed at least per month on average?

This farm tool factory originally planned to produce 400 farm tools every month. After technical innovation, the output in nine months exceeded the annual plan of 780 vehicles. How many pieces are produced on average every month now?

Party A and Party B walk in opposite directions from two places at the same time. They first met 70 kilometers away from a place, but they still walked at the original speed. They returned immediately after reaching the finish line and met again at a distance of 0/5 km from B/KLOC-. How many kilometers are the two places apart?

7.A train departs from A to B at 8: 00 a.m., and in the morning, 10 is 180 km away from A. It is known that AB is 540 km away. How many hours does it take to complete the journey?

Miss Wang and Miss Li bought the same book. Mr. Wang spent 256 yuan on eight books, while Mr. Li spent 192 yuan. How many more books did Mr Wang buy than Mr Li?

Sister and sister run in the same direction along the circular track. My sister runs 2 12 meters per minute, and my sister runs 187 meters per minute. They started from the same place. 16 minutes later, my sister caught up with my sister for the first time and asked about the length of the track.

6. Two warships, Party A and Party B, constantly patrol between two military bases. Ship A's speed is 12km/h, and ship B's speed is 9 km/h. Both ships set out from two bases at the same time, and it took exactly six hours to meet for the first time. How many kilometers are there between the two military bases?

There are 50 baskets of apples, which is twice less than the number of pears. How many baskets of apples and pears are there?

9. A batch of cloth was originally planned to make 1 1,800 sets of clothes. Because each set of cloth saved 0.2 m, 1 0,000 sets were made. How many meters does each piece of cloth use now?

1 1, two workers, Party A and Party B, work together to process a batch of parts and complete the task in 20 days. It is known that A makes three more pieces than B every day, and B takes five days off, so the number of parts completed by B is exactly half that of A. What is the total number of these parts?

13. There are two bags of rice. The weight of a bag of rice is 1.2 times that of b bag. If 5 kg is added to b bag, the two bags of rice will be the same. How many kilograms are there in two bags of rice

15, circular runway, finance minister 700 meters. Party A and Party B start from the same place at the same time and walk in opposite directions. A runs 7.5 meters per second and B runs 6.5 meters per second. They met in a few seconds.

Unit 3 Exercise in Grade Five 1

Author: anonymous article source: original hits on this site: 4433 Update time: 2003- 12-9

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Name score

1. Fill in the blanks (each space 1, *** 15)

1.90 cm2 = () sqm 875 cm2 = () sqm () sqm.

5 square meters and 8 square decimeters = () square meters = () square decimeters.

2.7 square meters = () square meters () square decimeter = 4.3 hectares = () square meters

2500 square centimeters = () square decimeter () square centimeters

2. The area of the triangle is 42 square decimeters, the base is 12 decimeters, and the height is ().

3. The base of parallelogram is 14cm, the height is 9cm, and the area is (); The area of a triangle with equal base and equal height is ().

The upper bottom of trapezoid is 3m, the lower bottom is 2m and the height is 2m. The area of this trapezoid is () square meters; The area of a parallelogram with the same height as the sum of the upper and lower bottoms is ().

II. True or false questions (2 points for each question, ***8 points)

1. Two triangles with the same area can be combined into a parallelogram. ()

2. The area of parallelogram is equal to twice the area of triangle. ()

3. Two identical trapezoids can form a parallelogram. ()

4. Extruding a rectangular frame into a parallelogram can reduce the area. ()

Three, multiple-choice questions (2 points per question, ***8 points)

1. An equilateral triangle must be a _ _ _ _ _ triangle. []

A. acute angle; B. right angle; C. obtuse angle

2. Two identical acute triangles can be combined into a _ _ _ _ _ _ []

A. rectangle; B. square;

C. parallelogram; D. trapezoid

3. Divide a parallelogram into two trapeziums at will, and the _ _ _ _ _ in these two trapeziums is always equal. []

A. high; B. area; C. Sum of upper and lower bottoms

4. In the picture on the right, the area of three graphs between parallel lines is _ _ _ _ _ _.

[ ]

A. The parallelogram has a large area.

This triangle has a large area.

C. the trapezoid has a large area.

D. the areas are all equal

Four, fill in the form (3 points per grid, ***24 points)

Verb (abbreviation of verb) Find the area of the shadow part (5 points for each question, *** 10).

Six, application questions (5 points per question, ***35 points)

1. The base of the triangle is 26 meters long, which is longer than the height 16 meters. What is the area of this triangle?

2. A parallelogram Gua Tian with a base length of 22.6m and a height of18m. If 45 trees are planted per square meter on average, how many trees will be planted?

There is a pile of cement, 24 bags above and 30 bags below. There are seven floors. How many bags are there in this pile of cement?

4. The People's Hospital made a triangle towel with a bottom height of 0.8m How many such triangles can a white cloth with a length of 6.4m and a width of 1.6m make?

The average stride of Xiaojun is 0.64 meters. He walked 168 steps from home to Kobayashi's, and came back and walked 170 steps. How many meters is Xiaojun's home from Kobayashi's?

6. The area of a trapezoid is 45 square meters, and the bottom is 10 meter; 5 meters above the bottom. What is its height?

7. There is a rectangular plot in the tea garden, where 96,000 tea trees are planted, with an average of 0.5 square meters per tea tree. How many hectares is this land? Given that the width of a rectangle is 100 m, how long is it?

1.3/7 × 49/9 - 4/3

2.8/9 × 15/36 + 1/27

3. 12× 5/6 – 2/9 ×3

4.8× 5/4 + 1/4

5.6÷ 3/8 – 3/8 ÷6

6.4/7 × 5/9 + 3/7 × 5/9

7.5/2 -( 3/2 + 4/5 )

8.7/8 + ( 1/8 + 1/9 )

9.9 × 5/6 + 5/6

10.3/4 × 8/9 - 1/3

1 1.7 × 5/49 + 3/ 14

12.6 ×( 1/2 + 2/3 )

13.8 × 4/5 + 8 × 1 1/5

14.3 1 × 5/6 – 5/6

15.9/7 - ( 2/7 – 10/2 1 )

16.5/9 × 18 – 14 × 2/7

17.4/5 × 25/ 16 + 2/3 × 3/4

18. 14 × 8/7 – 5/6 × 12/ 15

19. 17/32 – 3/4 × 9/24

20.3 × 2/9 + 1/3

2 1.5/7 × 3/25 + 3/7

22.3/ 14 ×× 2/3 + 1/6

23. 1/5 × 2/3 + 5/6

24.9/22 + 1/ 1 1 ÷ 1/2

25.5/3 × 1 1/5 + 4/3

26.45 × 2/3 + 1/3 × 15

27.7/ 19 + 12/ 19 × 5/6

28. 1/4 + 3/4 ÷ 2/3

29.8/7 × 2 1/ 16 + 1/2

30. 10 1 × 1/5 – 1/5 × 2 1

3 1.50+ 160÷40

32. 120- 144÷ 18+35

33.347+45×2-4 160÷52

34(58+37)÷(64-9×5)

35.95÷(64-45)

36. 178- 145÷5×6+42

37.8 12-700÷(9+3 1× 1 1)

38.85+ 14×( 14+208÷26)

39.(284+ 16)×(5 12-8208÷ 18)

40. 120-36×4÷ 18+35

4 1.(58+37)÷(64-9×5)

42.(6.8-6.8×0.55)÷8.5

43.0. 12× 4.8÷0. 12×4.8

44.(3.2× 1.5+2.5)÷ 1.6 (2)3.2×( 1.5+2.5)÷ 1.6

45.6- 1.6÷4= 5.38+7.85-5.37=

46.7.2÷0.8- 1.2×5= 6- 1. 19×3-0.43=

47.6.5×(4.8- 1.2×4)= 0.68× 1.9+0.32× 1.9

48. 10. 15- 10.75×0.4-5.7

49.5.8×(3.87-0. 13)+4.2×3.74

50.32.52-(6+9.728÷3.2)×2.

5 1.( 136+64)×(65-345÷23)

52.420+580-64×2 1÷28

53.(58+370)÷(64-45)

6.9+4.8+3. 1 0.456+6.22+3.78 15.89+(6.75-5.8)*6

4.02+5.4+0.98 5. 17- 1.8-3.2 13.75-(3.75+6.48)*6

3.68+7.56-2.68 7.85+2.34-0.85+4.66 35.6- 1.8- 15.6-7.2

3.82+2.9+0. 18+9. 1 9.6+4.8-3.6 7. 14-0.53-2.47

5.27+2.86-0.66+ 1.63 13.35-4.68+2.65 73.8- 1.64- 13.8-5.36

47.8-7.45+8.8 0.398+0.36+3.64 15.75+3.59-0.59+ 14.25

66.86-8.66- 1.34 0.25× 16.2×4 ( 1.25-0. 125)×8

3.6× 102 3.72×3.5+6.28×3.5 36.8-3.9-6. 1

15.6× 13. 1- 15.6- 15.6×2. 1 4.8×7.8+78×0.52 32+4.9-0.9

4.8× 100. 1 56.5×9.9+56.5 7.09× 10.8-0.8×7

25.48-(9.4-0.52) 4.2÷3.5 320÷ 1.25÷8

18.76×9.9+ 18.76 3.52÷2.5÷0.4 3.9-4. 1+6. 1-5.9

5.6÷3.5 9.6÷0.8÷0.4 4.2×99+4.2

17.8÷( 1.78×4) 0.49÷ 1.4 1.25×2.5×32 3.65× 10. 1

15.2÷0.25÷4 0.89× 100. 1 146.5-(23+46.5)

3.83×4.56+3.83×5.44 4.36× 12.5×8 9.7×99+9.7

27.5×3.7-7.5×3.7 8.54÷2.5÷0.4 0.65× 10 1 3.2×0.25× 12.5

(45.9-32.7)÷8÷0. 125 3. 14×0.68+3 1.4×0.032 5.6÷ 1.25÷0.8÷2.5÷0.4

7.2×0.2+2.4× 1.4 8.9× 1.0 1 7.74×(2.8- 1.3)+ 1.5×2.2

3.9×2.7+3.9×7.3 18- 1.8÷0. 125÷0.8 12.7×9.9+ 1.27

2 1×(9.3-3.7)-5.6 15.02-6.8- 1.02 5.4× 1 1-5.4

2.3× 16+2.3×23+2.3 9.43-(6.28- 1.57) 3.65×4.7-36.5×0.37

46×57+23×86 13.7×0.25-3.7÷4 2.22×9.9+6.66×6.7

10 1×0.87-0.9 1×87 10.7× 16. 1- 15. 1× 10.7 0.79× 199

4.8+8.63+5.2+0.37 5.93+0. 19+2.8 1 1.76+0. 195+3.24

2.35+ 1.7 13+0.287+7.65 1.57+0.245+7.43 6.02+3.6+ 1.98

0. 134+2.66+0.866 1.27+3.9+0.73+ 16. 1 7.5+4.9-6.5

3.07-0.38- 1.62 1.29+3.7+2.7 1+6.3 8-2.45- 1.5

3.25+ 1.79-0.59+ 1.75 23.4-0.8- 13.4-7.2 0.32×403

3.2+0.36+4.8+ 1.64 1.23+3.4-0.23+6.6 0.25×36

12.7-(3.7+0.84) 36.54- 1.76-4.54 0.25×0.73×5

7.6×0.8+0.2×7.6 0.85× 199 0.25×8.5×4

1.28×8.6+0.72×8.6 12.5×0.96×0.8 10.4-9.6×0.5

0.8×(4.3× 1.25) 3. 12+3. 12×99 28.6× 10 1-28.3

0.86× 15.7-0.86× 14.7 2.4× 102 2.3 1× 1.2×0.5

14-7.32-2.68 2.64+8.67+7.36+ 1 1.33 70÷28

(2.5-0.25)×0.4 9. 16× 1.5-0.5×9. 16 3.6-3.6×0.5

63.4÷2.5÷0.4 4.9÷ 1.4 3.9÷( 1.3×5)

(7.7+ 1.54)÷0.7 2.5×2.4 2.7÷45 15÷(0. 15×0.4)

0.35× 1.25×2×0.8 32.4×0.9+0. 1×32.4 15÷0.25

4.5÷ 1.8 4.2÷3.5 930÷0.6÷5

This is a calculation problem, and 1. Use a piece of land, including 1/5 kinds of corn, 1/6 kinds of vegetables and the rest kinds of watermelons. What is the proportion of watermelons planted in this land?

There are 24 boys and 20 girls in one class. How many times more boys than girls? What is the percentage of boys to girls?

Students take part in environmental protection action. The fifth grade cleared 3/5 tons of garbage, less than the sixth grade 1/8 tons. How many tons of garbage were removed in the fifth and sixth grades?

4. A rectangular iron plate with a length of 40 cm and a width of 30 cm, the four corners are cut off and the sides are 4 cm long, and then welded into a box without a cover. How many liters is its volume?

5. A car traveled192km in the first 3 hours and 58km/h in the last 2 hours. What is the average speed of this car?

(1) There are several goldfish in the fish tank, of which red goldfish accounts for all and black goldfish accounts for all. What percentage of all goldfish are red goldfish and black goldfish?

It took the road repair team three days to repair half of the whole road. On the first day, the whole road was repaired. On the second day, how many parts of the whole road were repaired?

(3) Red Star Primary School will build a rectangular playground 60 meters long and 45 meters wide. Pave 10 cm thick concrete first, and then pave 4 cm thick cinder. How many cubic meters does concrete need more than cinder?

(4) How many square decimeters of iron does it take to make an uncovered rectangular tin can with a length of 85cm, a width of 50cm and a height of 50cm?

(5) Badge Factory finished processing a batch of medals for the 2008 Olympic Games in one month. It was all processed in the first half of the month. How much less was processed in the second half of the month than in the first half?

(6) A cuboid fuel tank with a length of 70cm, a width of 44cm and a height of 25cm. How many liters of oil can this tank hold at most? If the price of gasoline is calculated at 3.76 yuan per liter, how much does it cost to fill up such a box of gasoline?

1. Xiaoming reads books, reading an average of 6.25 pages a day for the first 4 days and 24 pages for the last 3 days. How many pages does Xiaoming read every day this week?

The following is the temperature of a certain place in four periods of a day. Calculate the average temperature of this day.

3. A wooden box, length 1.2m, width 0.8m and height1m.. If it is painted all around the outside, what is the area of the painting?

4. There is a kind of rectangular steel, which is 2 meters long and the cross section is a square with a side length of 5 centimeters. Each cubic decimeter of steel weighs 7.8 kilograms. How much does this square steel weigh?

5. There is a fish pond, with a length of 18m, a width of 12m and a depth of 3.5m It is necessary to coat a layer of cement around the fish pond to prevent water seepage. If 5 kilograms of cement is used per square meter, how many kilograms of cement does a * * need?

6. Cut a cube with a volume of 64 cubic centimeters from a cuboid with a length of 6 centimeters. What is the original surface area of this cuboid?

7. What is the smallest number divisible by both 6 and 9?

8. A rectangular piece of paper, 48 cm long and 36 cm wide. Cut this paper into square paper with the same size and no excess. What is the longest side of the square?

1 class and class 5 (1) students do exercises. There are 3 people in a row for every 8 people and 3 people in a row for every 10 people. How many students are there in this class at least?

Xiaoming walks 45 minutes from school to Children's Palace, and Xiaolin walks 48 minutes from school to Children's Palace. How many points did each of them get? Who is faster?

3. A cuboid reservoir, measured from the inside, is 4.5m long, 4m wide and 1 m deep. How many square meters is this reservoir? There is 14.4 cubic meters of water in the pool. How deep is it?

The tractor plowed a field. What is the percentage of cultivated land in the morning and afternoon?

1. Xiaohong's height 156 cm, Xiao Fang's height 1.52 m, how much is Xiaohong taller than Xiao Fang?

2.50 kg rapeseed can extract 15 kg oil. According to this calculation, how many kilograms of oil can be extracted from 5 tons of rapeseed?

3. Xiaoming's home is away from school 1.5km, and Xiaonan's home is away from school 1km. How close is his home to the school?

4. An African ostrich is about 150kg 500g, and a pig is about123.06kg. How many kilograms is an ostrich heavier than a pig? Write the result as a compound number.

The sowing width of a seeder is 3 meters, and the seeder travels 5 kilometers per hour. According to this calculation, how many hectares can be sown in 2 hours?

4. The road team repaired 1.078km on the first day, and 0.456km more on the second day. How many kilometers did the road team build in two days? I hope primary school students can save 40.25 yuan by repairing desks and chairs, and 3.7 yuan saves less money by binding books than by repairing desks and chairs.

Xiao Liang's father bought him a computer desk and chair. The price of the chair is 45 yuan, which is cheaper than the table 12.5 yuan. How much is a table?

6. In the long jump competition of the sports meeting, Xiaohong scored 2.85 meters, Xiaoming jumped 1.25 meters more than Xiaohong, and Xiaohong jumped 0.23 meters more than Xiao Ju. Who won the first place in the long jump and why?

7. Students in Zhangzhuang Primary School spent 40.25 yuan on repairing desks and chairs, more than 3.7 yuan who bound books. How much does it cost to bind books (equation solving)?

8. Tiger walked from home to school in the morning1.3km. After walking 0.3 km, I found that I didn't bring my math exercise book, so I went home to get it. So how many kilometers did he walk to school than usual?

9. suguo supermarket shipped 0.3 1 ton of cantaloupe, and watermelon was 2.75 tons more than cantaloupe. How many tons did the two melons ship?

10, Aunt Zhang packed a basket of vegetables and sold them at the farmer's market. The original weight of baskets and vegetables was 7.4 kilograms. After selling some vegetables, she went home and weighed it, 3.6 kilograms. How many kilograms of vegetables did she sell?

1 1, three people take part in the 60-meter race. Liu Mingyong took 9.6 seconds, Li Qiang was 0.5 seconds slower than him and Zhao Liang was 0.2 seconds faster than Li Qiang. What's their ranking?

12, the school used 200 yuan to buy books, science and technology books 87 yuan 50, story books 32 yuan 04. How much is left?

13, A and B are 220 meters apart, and Obana Xiaohong comes from A and B respectively. Xiaohua walked 85.2 meters, Xiaohong walked 70.5 meters, how many meters were separated between them?

14, Xiaoming bought a pen and a diary. The unit price of pen is 12.7 yuan, and the price of diary is 4.5 yuan. Xiao Ming pays 20 yuan, a salesman. How much should he get back?

15, a bottle of oil weighs 3.4 kg. Half of it is used, and the bottle weighs 1.9 kg. The original bottle was as heavy as oil.

16, build a highway, 134.5 km has been repaired, and the rest is less than that repaired 13.6 km. What is the total length of this highway?

17, a bamboo pole is vertically inserted into the pool. The mud settling part of bamboo pole is 0.6m, the dew part is 0.7m, and the pool depth is 2m. How long is this bamboo pole?

18, a 4.8-meter-long bamboo pole is vertically inserted into the pool. The muddy part of bamboo pole is 0.3m, and the exposed part is1.75m.. What is the depth of the swimming pool?

19 Xiao Qiang spent 15 yuan went shopping in the supermarket. The prices of some commodities in the supermarket are as follows: notebook (notebook), pencil (branch), ruler (root), knife (handle), triangular pen (branch) 6.30 yuan 0.60 yuan 1.20 yuan 2.4 yuan 4.50 yuan 6.70 yuan ① Xiao Qiang can buy at most.

The circumference of the triangle is 16.4 cm, in which the first side and the second side are 5 cm each. How long is the third side?

2 1, Xiao Zhang, Xiao Li and Xiao Wang weigh themselves. The total weight of Xiao Zhang and Xiao Li is 90.8 kg, and the total weight of Xiao Wang and Xiao Li is 88.5 kg. How many kilograms is Xiao Zhang heavier than Xiao Wang?

Twenty-two families planted three responsibility fields. The first one is 1080 m2, which is more than the second one 15.7 m2, and the third one is 8.5 m2 less than the first one. Please ask at least two questions and answer them according to what you know.

Dad is 0.52 meters taller than Xiaohong and 0.2 1 meter taller than mom. How many meters is mom taller than Xiaohong?

There is an infrared remote control tank toy in the supermarket, the price is 130.00 yuan, which is cheaper after discount 13.00 yuan. Xiaoming is going to buy this toy tank with the money from buying two mini racing cars, each 55 yuan. Does he have enough money? If not, how much money is left?

25. This year, the cement plant allocated 3.324 million yuan for pollution control, 2.347 million yuan for sewage tank renovation, and another 855,000 yuan. How many million yuan does the factory have for pollution control now?

26.b is in the middle between A and C. After the car A is released from A for 48.5 kilometers, it is still 14.5 kilometers away from B. At this time, how many kilometers is the car from C?

27. The original price of a children's suit in Asia is 125.90 yuan, and the promotion price for celebrating June 1st is 98.80 yuan. How much cheaper?

28. Xiao Wang weighs 36.5 kg, Xiao Li weighs 4 1.4 kg, and sumo wrestlers weighs 125.8 kg. How many kilograms does this athlete weigh more than Xiao Wang and Xiao Li combined?

29. Xiao Qiang is 0. 19 meters higher than Xiao Fang, Xiao Fang is 22 centimeters shorter than Tiger, and Tiger is several meters higher than Xiao Qiang.

30. Someone bought an item and paid it to 50 yuan, the shop assistant. The clerk misread the decimal point of the commodity price and gave him 46.75 yuan. He said he found too much. What is the price of this project?

3 1, the fruit shop sent three baskets of apples, 30.5 kg each. How many kilograms did a * * * send? If the price per kilogram of apples is 2.6 yuan, how much can these apples earn?

32. Average daily electricity consumption of schools 17.3 kWh. How many kWh will be used in May? If you charge 0.5 yuan per kilowatt hour, how much electricity will you pay this month?

33. The height of the Lingshan Giant Buddha in Wuxi is 88 meters, which is 1. 15 times that of the Leshan Giant Buddha in Sichuan, 0.6 meters more. How high is Leshan Giant Buddha in Sichuan?

The fruit shop sells 32.5 kilograms of apples every day, which is 0.9 times that of the first day every two days.

How many catties of apples do you sell the next day? How many kilograms do you sell the next day?

35. Xiaoming bought two composition books in the bookstore, one is 10.8 yuan and the other is 7.6 yuan. He gave it to 20 yuan, so how much should he get back?

1, the turnover of Li Hong Supermarket on Monday was 23,500 yuan, and the turnover on Tuesday was 1.3 times that on Monday. How much more than 10 thousand yuan a day (the result is reserved to one decimal place)

2. The length of a window glass is 1.3m, and the width is 1. 1m, so how many square meters of glass is needed to make 12 such windows (the result is an integer).

3. The length of parallelogram land is 3.5m longer than its height. Known base length16.8m. What is the area of this land?

3 yuan per kilogram of apples, 2.2 yuan per kilogram of oranges, and Xiaoming bought 5 kilograms of apples and oranges with 30 yuan money respectively. How much should he get back?

5. The average of the three numbers A, B and C is 5, and half of the two numbers B and C is 4.5. What's the number of a?

6. The school handicraft group made 28 handicrafts with 95.2 square decimeters of colored paper. How many square decimetres of paper does each handicraft use on average?

7. Xiao Minghua 16.5 yuan bought 5 kilograms of apples, and Xiao Honghua 2 1.7 yuan bought 7 kilograms of apples. Who bought it more expensive? 8. Four giant pandas ate 36.24 kilograms of bamboo leaves in three days. How many kilograms of bamboo leaves does each giant panda eat on average every day?

9. The distance between Party A and Party B is 66 kilometers. It takes 1.2 hours for the ship to get from A to B, and 1 hour for the return trip. What is the average speed of the ship going back and forth?

10, 120 kilograms of rapeseed can extract 38 kilograms of rapeseed oil, and how many kilograms of rapeseed oil can be extracted per kilogram (the result is retained after one decimal point).

1 1, a rectangular vegetable field, which is 1 1 m long and 2m longer than its width. In this vegetable field, 445.5 Jin of cabbage is harvested. How many Jin of cabbage is harvested per square meter on average?

12, a batch of 75 tons of goods has been shipped six times, leaving 4 1.4 tons. How many tons are shipped on average, and how many times will the rest be shipped (the result remains an integer)

13, class five (1) has 45 people joining the interest group, which is 1.5 times that of class five (2). How many people in Class Two joined the interest group?

14, the average of five numbers is 19.68, the average of the first three numbers is 18.9, and the average of the last three numbers is 29.4. What's the middle number?

15, a flour mill 1 hour can grind 5.6 kilograms of flour, so how many kilograms can this flour mill grind in 4.5 hours?

16, the circumference of a square is 5.6 decimeters. How many square decimetres is the area of this square?

17, Xiaoming and his father play electric plane. When buying a ticket, Xiao Ming pays 10 yuan and takes it back to 2.5 yuan. The fare of electric plane is half that of adults, so how much are the student tickets and adult tickets?

18, Xiaoming spent 48.64 yuan in pocket money in March, which is 3.2 times that of Xiaohong. How much pocket money does Xiaohong have this month?

19, the area of a rectangle is 2 1 square decimeter, and the length is 5 decimeters. What is its circumference?

20. Miss Wang bought 6 Jin of oranges with 7.8 yuan. How much are oranges per kilogram? 1 Yuan How many Jin of oranges can I buy (except two decimal places).

2 1, a batch of coal, burning 3.6 tons a day, can burn for 30 days, if burning 2.4 tons a day, how many days can it burn?

22, a football is 46.8 yuan, which is three times cheaper than a volleyball. 1.2 yuan, what is the price of a volleyball (equation solving)?

23. The oil is 80.8kg. How much can an oil drum with a capacity of 4.7kg be filled (the number must be kept as an integer).

How much does it cost to buy 5.2 kilograms of apples per kilogram of apples in 3.2 yuan? If I pay 20 yuan, how much should I get back?