People's education printing plate fourth grade mathematics second volume application problem
1. A chemical fertilizer plant 1 month produces 3 10 tons of chemical fertilizer, 400 tons in February and 490 tons in March. How many tons of chemical fertilizer are produced on average every month?
2. A horse eats12kg of grass every day. According to this calculation, how many kilograms of grass can 25 horses eat a week? (Calculated in two ways)
The worker master Wang and his apprentice make machine parts. Master Wang earns 45 pounds an hour, while his apprentice earns 28 pounds an hour. Master Wang works 6 hours and his apprentice works 8 hours. How many machine parts did he make?
The factory has 8000 kilograms of coal, which was originally planned to burn for 25 days. Due to the improvement of the stove, it actually burned for 32 days. How many kilograms are saved on average every day compared with the original plan?
5. The construction site needs 1280 bags of cement, and all four transports need 8 carts. How many bags of fertilizer can a cart carry at a time? (Calculated in two ways)
This farm tool factory produced 4650 farm tools in the first half of the year and 5382 farm tools in the second half. How many farm tools are produced on average every month throughout the year?
7. The garment processing department can make 24 sets of adult uniforms and 30 sets of children's clothes with120m fabric. How many meters are used for each set of children's clothes less than adults?
8. A chicken farm sold12,300 chickens in April, 200 fewer in May than in April. How many chickens are sold in two months?
9. A factory originally planned to produce 4,800 farm tools a year, but actually completed the task in 10 month. How much more farm tools are actually produced each month than originally planned?
10. One machine can process 320 parts in 8 hours. According to this calculation, how many hours does it take to process 2000 parts with 5 machines?
1 1. A coal mine plans to produce 38,400 tons of coal in April. After technical transformation, the average daily output increased by 256 tons compared with the original plan. How many tons of coal was actually produced in April? (Calculated by 30 days)
12. There are 6 people in the first group, and the average score of 5 people in the Chinese exam is 85. After adding Wang Gang's score, the average score is 87. What's Wang Gang's exam score?
13. Two water pipes simultaneously discharge water into the pool. The discharge of the thick pipe is15t per hour, and that of the thin pipe is 1 1 ton per hour. How many tons of water can this pool hold in eight hours? (Calculated in two different ways)
14. The rectangular playground is 50m long and 40m wide. After the expansion, the length and width increased by 5 meters respectively. How many square meters has the playground area increased after the expansion?
15. The length of a rectangle is 2 1 cm, which is three times the width. What is the circumference and area of this rectangle?
16. One ton of waste paper can produce 700 kilograms of paper. If one kilogram of paper can make 25 exercise books, how many exercise books can be made from 12 tons of waste paper?
17. It takes 4 tapes to record a Qigong report, and it takes 30 minutes to record a full tape. How many hours has this report been recorded?
18. A bulldozer can pave 600 meters in 3 hours. If it spreads 20 meters per hour, how many meters can it spread in 8 hours?
19. Farmers in Lizhuang transported wheat to the grain depot. On the first day, they shipped 10 cars, and on the second day, they shipped 7 cars, each with 2 tons of 400 kilograms of wheat. How many kilograms were transported in two days? How many tons and kilograms?
20. 100 wet brick weighs 450kg, and each brick loses weight after drying 850g. 100 how many kilograms does the wet brick weigh after drying?
2 1. An automatic packaging machine packs 20 seconds 135 pieces of sugar. According to this calculation, how many pieces of sugar can this machine hold 1 hour?
22. A steel pipe is 9 meters long and has been used for 3.6 meters. How many meters is the rest longer than the used one?
23. A paper mill made paper 1.56 tons in July and 0/.68 tons in August, which was 0.74 tons less than that in July and August. How many tons of paper were produced in September?
24. The factory canteen burned 30 tons of coal in the first half of the year, about 2.45 tons less than that in the first half. How many tons of coal were burned in the second half of the year?
25. A pair of cloth shoes 7.8 yuan, a pair of sneakers 9.5 yuan, how much is a pair of sneakers more expensive than a pair of cloth shoes?
26. There are two granaries. The first granary has 56.5 tons of grain, 9 tons less than the second granary. How many tons of grain are there in these two granaries?
27. Team A and Team B jointly paved a 94.6-kilometer-long road. Team A paved 32.5 kilometers and Team B paved 29.5 kilometers. How many kilometers are left unpaved?
28. The circumference of an isosceles triangle is 1m and the waist length is 0.4m How long is the base of this triangle?
29. A flour mill grinds 800 kilograms per hour. According to this calculation, how many kilograms of flour can six flour mills grind in five hours? (Answer in two ways)
30. A pile of ***800 tons of coal can be transported 16 times by five trucks. How many tons can each truck transport at a time?
3 1. Cars travel 300 kilometers in 6 hours and trains travel 600 kilometers in 6 hours. How many kilometers does the train travel more than the car per hour?
33. In a week's time, the highest temperatures measured by Xiangyang Primary School Meteorological Team every day were: 365, 438+0, 365, 438+0, 34, 32, 33, 30 and 33 degrees respectively. What is the highest average temperature this week?
34. Xiaohua walked 4 kilometers and 680 meters, and it took 1 hour 18 minutes. How many meters is the average branch?
35. A 3-ton truck, loaded with 7,000 kilograms of wood, has to cross a bridge with a weight limit of 1 1 ton. Calculate, can the truck cross the bridge?
The width of the 36.28-row seeder is 4m. Tractor traction, 5 kilometers per hour, how many hectares of land can be sown?
37. two piles of goods, a and b, 8000 kg. It is known that the weight of the goods in pile A is four times that of the goods in pile B. How many kilograms do you think there are in these two piles?
38. A train traveled 366 kilometers in six hours in the morning and 276 kilometers in four hours in the afternoon. How many kilometers did you drive on average in the afternoon than in the morning?
39. A factory used coal 120 tons in the first half of the year and coal 102 tons in the second half. According to 80 yuan, how much is the monthly coal consumption saved in the second half of the year compared with that in the first half?
40. A forest farm planted 65,438+0,480 trees the year before last. The number of trees planted last year was twice that of the year before. The total number of trees planted this year is 420 more than the previous two years. How many trees will be planted this year?
4 1. 100 kg of rice can be milled by 75 kg, and 1 kg of rice can be milled by how many kg?
42. 1 kg soybean can yield 0.38 kg oil, and 100 kg soybean can yield how many kg oil? 1000 kg of soybeans?
43. Teacher Zhang bought 10 pen for 43.20 yuan. How much is each pen? 100 How much is this pen?
44. The number A is 3.8 and the number B is 38. Put two zeros at the end of them. So how many times is the number b?
45. The school spent 65.76 yuan on football and basketball. It is known that it spent 42.86 yuan on football. How much did it cost to buy basketball?
46. The students collected tree seeds. Class One collected 32.56 kilograms, Class Two collected 38.45 kilograms. How many kilograms did the two classes collect?
47. Miss Li spent 24.28 yuan on a math reference book and 23.76 yuan on a Chinese reference book. He paid 50 yuan, a shop assistant. How much should he get back?
48. The worker's uncle built a road. On the first day, he built 18.65 meters. The next day, he built 5.6 meters more than the first day. How many meters did he build in two days?
50. The students went for a spring outing. Each car transports 48 people, and it takes 3 cars to transport all teachers and students twice. How many teachers and students took part in the spring outing?
5 1. Everyone in the binding workshop binds 640 books per hour. According to this calculation, how many books will 8 hours 12 people bind?
52. The fleet carried out fuel-saving activities, and 12 vehicles saved 7,200 kilograms of fuel a year. How many kilograms of gasoline does each car save on average every month?
53. A telephone in 320 yuan, "color TV" is eight times that of a telephone, and the computer 1000 yuan is more than three times that of "color TV". How much is a computer?
54. Two workshops produce parts. Five days later, Workshop A produced 1520 parts and Workshop B produced 1280 parts. If you work 8 hours a day, how many parts does workshop B produce per hour less than workshop A?
55. According to statistics, blue whales can swim108m in 3 hours, and dolphins can swim 245m in 5 hours. How many meters does a blue whale swim less than a dolphin per hour?
56. A production team of 25 people processed 1.500 parts a day, and then transferred 8 people. According to this calculation, how many more parts are processed by the production team every day than before?
57. Hualian Department Store sells 90 sets of "Antarctic" cotton underwear a day, 38 sets in the morning, and each set of cotton underwear is 2 18 yuan. How much did it cost in the morning than in the afternoon?
58. This grain processing factory uses two flour mills to grind 28,800 kilograms of flour for five days and work eight hours a day. The first mill grinds 3 14 kilograms per hour, and how many kilograms does the second mill grind per hour?
59. Xiaogang read a book. On the first day, he read 10. After that, he read five more pages than the day before. On the last day, he just finished reading 40 pages. How many days did he study?
60. Xiaohua has read 45 pages of books, but what he hasn't read is 8 pages less than what he has read three times. How many pages are there in this book?
6 1. Master and apprentice process a batch of parts at the same time. The master processes 125 pieces per hour, and the apprentice processes 100 pieces per hour. 8 hours to complete the task, how many parts does the master process more than the apprentice? How many parts do master and apprentice process?
62. It is known that the average of A, B and C is 268, and the number of D is 148. What is the average of these four numbers?
63. Students took part in environmental protection activities. 6 1 class has 42 students, with an average of 80 square meters each, and 62 classes have 38 students, with an average of 2,800 square meters. How many square meters are there in each of the two classes?
64. Xiaohua rides 20 kilometers and 400 meters, which takes 1: 20. How many kilometers and meters does he ride per hour on average?
65. The factory delivered a batch of raw materials, of which 400 kilograms have been delivered 15 tons, and the remaining 500 kilograms are more than three times that delivered. How many kilograms of raw materials are there? How many tons and kilograms?
66. Typists type 150 words per minute. How many hours and minutes does it take to type a 30000-word manuscript?
67. A rectangular paddy field is 200 meters wide and twice as long. How many hectares is this rice field? If 6500 Jin of rice is collected per hectare of paddy field, how many Jin of rice is collected in this land?
68. 10 ton wheat can be ground to 8.5 tons, and 100 kg wheat can be ground to how many tons?
69. 100 tons of seawater contains 3 tons of salt, and 10 tons of seawater contains how many tons of salt?
70. The hardware factory * * * produces 3000 kilograms of nails, which are packed in 100 wooden cases, with the remaining 500 kilograms. How many wooden cases do you need?
7 1. A bag of rice consumes 32. 18 kg, and 17.82 kg. How much kg is this bag of rice?
72. A football is 48.36 yuan and a basketball is 54.27 yuan. Teacher Wang spent 150 yuan to buy a football and a basketball. How much should she get back?
73. The length of a rectangle is 0.54 meters, which is 8 centimeters more than its width. What is the circumference of this rectangle?
74. Two wires, the first one is 48.3 meters long, which is 6.5 meters longer than the second one. After the first one used 9.4 meters, how many meters less than the second one?
75. A chair costs 35.4 yuan, which is cheaper than a table 16.2 yuan. The school bought 65,438+000 sets of desks and chairs. How much will it cost?
76. A rope is divided into three sections, the first and second sections are 38.7m, the second and third sections are 41.6m, and the first and third sections are 39.7m.. How long are these three pieces of rope?
77. Warehouse A has 58.4 tons of grain and warehouse B has 44 tons of grain. How many tons of grain are shipped from warehouse A, and the grain in warehouse B is twice as much as that in warehouse A?
78. The school bought 320 sets of desks and chairs, each with 55 yuan and each with 36 yuan. How much did the school spend? (Answer in two ways)
79.7 Workers can process 2632 pieces of clothes in 8 days. According to this calculation, if three more workers are added, how many clothes can be processed by 1 day?
80. There are 132 pear trees in the orchard, 44 fewer than peach trees. There are twice as many apple trees as pear trees and peach trees. How many apple trees are there in the orchard?
8 1. It took 360 yuan for the school to buy volleyball for its students. The money spent on football is twice less than that of 60 yuan, and just twice as much as that of basketball. How much did the school spend on basketball?
82. The school assigned two classes the task of cleaning a green land with a length of 39 meters and a width of 20 meters. There are 40 students in Class A and 38 students in Class B. How many square meters should each class clean?
83. Three baskets of apples weigh 1 10.5 kg. If we take 18.6 kg from the first basket, 23.5 kg from the second basket and 20.4 kg from the third basket, then the remaining apples in the three baskets weigh the same. How many kilograms were there in the original three baskets?
84. There are 64 pine trees in the park, less than willow trees 16. The number of poplars is three times that of pine and willow combined. How many poplars are there in the park?
85. On Children's Day, two groups of students spent three hours making 240 flowers. The first group made 44 flowers every hour, and the second group had six people. How many flowers does everyone make per hour on average?
86. The migrant workers' team is planning to repair the canal by 84 meters a day, and it will be completed in 34 days. As a result, 102 meter was built in one day, which can be completed several days ahead of schedule.
87. A rectangular vegetable field with an area of 1 hectare and a length of1.25m.. A wheat field is 250 meters long. These two plots are equal in width. What is the area of the wheat field? How many hectares?
88. A car travels from place A to place B, 90 kilometers in the first two hours and 48 kilometers in the third hour, just arriving at place B. How many kilometers does the car travel on average per hour?
89. Harvest a batch of apples in the orchard. Small baskets can hold 25 kilograms per basket, which requires 28 baskets. If it is replaced by 10 big basket, there are still 50 kilograms left. How many kilograms can each big basket hold on average?
90. There are 48 students in Class A and Class B, each of whom made 16 paper flowers and sent them to kindergarten. How many flowers did a * * * send?
The distance between 9 1.A and b is 456 kilometers. How many hours does it take for the train to travel from A to B at an average speed of 76 kilometers per hour?
92. There are two grain warehouses. If the first warehouse is loaded with 2500 kilograms, the two warehouses have the same amount of food. It is known that the second warehouse has 50200 kilograms of grain. How many catties did the original two grain depots have?
93. The master produces 64 machine parts per hour and the apprentice produces 48 parts per hour. How many hours does it take for the apprentice to complete the parts produced by the master in three hours?
94. A rectangular vegetable field, length120m, width 60m. If a tomato is planted every 12 square decimeter, how many tomatoes can be planted in this vegetable field? If each tomato charges 3 kilograms, how many kilograms does a tomato charge?
95. A has 14.8 yuan and B has 15.2 yuan. They want to buy a football together. The price of a football is twice their money. How much is a football and how much do they lack?
96. A machine plows 15 hectares in three hours. According to this calculation, how many hours does it take for five machines to plow 75 hectares?
97. There are 14 boxes of duck eggs in the shop. Sold 250 kilograms, leaving 4 boxes of 20 kilograms. How many kilograms are there in each box of duck eggs?
98. bright primary school donated 240 books to students in mountainous areas, twice as many as the fifth grade, and the sixth grade was more than the fifth grade 120. How many books did you donate per grade on average?
99. The grain store delivered 20 bags of rice and 20 bags of flour, each containing 90 kilograms of rice and 25 kilograms of flour. How many kilograms more rice is brought in than flour? (Answer in two ways)
100. Two ropes * * * are 48.4m long. After cutting 6.4 meters from the first rope, the second rope is 6 meters more than the remaining two of the first rope. How long are the two ropes?
Summary of Mathematical Operation Skills in the Fourth Grade of Primary School
? (1) Write down three digits for the addition of two digits.
1, aligned with the same number;
2. Starting from the unit;
3. When the number of digits reaches 10, enter 1 into ten digits.
(2) Do a two-digit subtraction with a pen, and remember three things.
1, aligned with the same number;
2. Reduce from one place;
3. If the number of digits is not enough, subtract 1 from the number of digits, add 10 to the number of digits and then subtract.
(3) Calculation rules of mixed operation
1, in the formula without brackets, only addition and subtraction or multiplication and division can be performed from left to right;
2. In the formula without brackets, if there are multiplication and division and addition and subtraction, the multiplication and division should be calculated first, and then the addition and subtraction should be calculated;
3. If there are brackets in the formula, count the brackets first.
(D) four-digit reading method
1, read in order from the high order, thousands, hundreds, and so on;
2. There is a zero or two zeros in the middle, and only one "zero" is read;
No matter how many zeros there are, don't read the last number.
(5) Four-digit writing
1, written in order from the high order;
2. Write a few words in thousands, a few words in hundreds, and so on. Write "0" in the middle or at the end.
(6) Four-digit subtraction should also pay attention to three items.
1, aligned with the same number;
2. Reduce from one place;
3. Which figure is not enough to reduce? Retract 1 from the previous position, add 10 to the standard position, and then subtract.
(7) the law of one-digit multiplication by multi-digit multiplication
1, starting from the unit, multiply each digit in multiple digits by one digit in turn;
Whoever gets the highest score will be promoted several times.
(8) Divider is the division rule of single digits.
1. Divide the dividend by the first digit of the dividend every time starting from the high digit of the dividend. If it is less than the divisor, try the division of the first two digits again.
2. Write the quotient where the divisor is divided;
3. For each quotient, the remainder must be less than the divisor.
(9) The multiplication rule that a factor is a two-digit number.
1, first multiply the number on the two-digit number by another factor, and the last digit of the number is aligned with the two-digit number;
2. Multiply the number on the ten-digit number by another factor to get that the last digit of the number is aligned with the ten-digit number;
3. Then add up the multiplied numbers twice.
(10) The divisor is the division rule of two digits.
1. Starting from the high order of the dividend, try to divide the first two digits of the dividend by the divisor. If it is less than the divisor,
2. Write the business on any one except the bonus;
3. For each quotient, the remainder must be less than the divisor.
(eleven) the reading rules of ten thousand books.
1, read ten thousand levels first, and then read one level;
2, 10,000-level numbers should be read according to the ten-level reading method, and then add a word "10,000" at the back;
3. Don't read the last digit of each level, no matter how many zeros there are. Other numbers have a read-only "zero" with one zero or several consecutive zeros.
(12) Multi-digit reading rules
1, starting from the high position and reading down one level at a time;
2. When reading 100 million or 10,000 levels, read according to a series of reading methods, and then add the words "100 million" or "10,000" at the back;
3. Don't read the zero at the end of each level, other numbers have a zero, or read only one zero for several consecutive zeros.
(XIII) Comparison of decimal dimensions
Compare the sizes of two decimals, first look at their integer parts. The number with large integer parts is large, so is the number with large integer parts, the number with large decimal places is large, the number with large decimal places is also large, and so on.
(14) decimal addition and subtraction operation rules
To calculate decimal addition and subtraction, first align the decimal point (that is, align the numbers on the same digit), then calculate by integer addition and subtraction, and finally align the decimal point position on the horizontal line and point the decimal point.
Calculation Rules of (15) Decimal Multiplication
To calculate decimal multiplication, first calculate the product according to the multiplication law, then look at the decimal places in the factor, count the decimal places from the right side of the product and point to the decimal point.
(16) divisor is the law of integer division.
Dividers are fractional divisions of integers. Divide according to the law of integer division. The decimal point of quotient should be aligned with the decimal point of dividend. If there is a remainder at the end of the dividend, add 0 to the remainder and continue the division.
(17) Division algorithm with divisor as decimal.
Divider is the division of decimals. First, move the divisor decimal point to make it an integer. The decimal point of the divisor is shifted to the right by several digits, and the decimal point of the dividend is also shifted to the right by several digits (the digits are not enough to make up the 0 at the end of the dividend), and then it is calculated by fractional division with the divisor as an integer.
(18) Steps to Solve Application Problems
1, find out the meaning of the problem, find out the known conditions and problems, analyze the quantitative relationship in the problem, and determine what to calculate first, then what to calculate, and finally what to calculate;
2. Determine how to calculate each step, list formulas and work out numbers;
3. Test and write the answers.
(nineteen) the general steps of solving application problems with column equations
1, find out the meaning of the problem, find out the unknown, and express it with x;
2. Find out the equal relationship between quantity and quantity in the application problem and make the equation;
3. Solve the equation;
4. Test and write the answers.
(20) Addition and subtraction of fractions with the same denominator
Add and subtract fractions with the denominator, the denominator remains the same, and only the numerator is added and subtracted.
(twenty-one) the addition and subtraction rules of the same denominator and the same fraction.
To add and subtract fractions, first add and subtract the integer part and the fraction part respectively, and then combine the obtained numbers.
(22) Addition and subtraction of fractions with different denominators
The addition and subtraction of fractions with different denominators are divided first, and then calculated according to the addition and subtraction law of fractions with the same denominator.
(twenty-three) the calculation rules of the score multiplied by the integer.
Multiply a fraction by an integer, and use the product of the numerator of the fraction multiplied by the integer as the numerator, with the denominator unchanged.
(twenty-four) the calculation rules of the score multiplied by the score.
Fractions are multiplied by fractions, the product of numerator multiplication is numerator, and the product of denominator multiplication is denominator.
(twenty-five) a number divided by a fraction of the calculation rules.
A number divided by a fraction is equal to the number multiplied by the reciprocal of the divisor.
(26) Methods of converting decimals into percentages and converting percentages into decimals.
To convert decimals into percentages, just move the decimal point two places to the right, followed by hundreds of semicolons;
Convert percentages to decimals, remove the percent sign, and move the decimal point two places to the left.
(27) Methods of converting fractions into percentages and converting percentages into component numbers.
To turn a fraction into a percentage, usually first turn the fraction into a decimal (except for three decimal places), and then turn the decimal into a percentage;