Application problem in primary school is one of the compulsory contents in primary school mathematics. Therefore, the following are the classic application questions and answers of primary school mathematics I collected for your reference only.
Questions and Answers on Classic Application of Mathematics in Primary Schools 1 1, a tank of water, used 1/2 and 5 barrels, with 30% left. How many barrels of water are there in this tank?
2. The length of a steel pipe is10m. Cut off 7/ 10 for the first time, and cut off the remaining 1/3 for the second time. How many meters are left?
3. After 2/3 of the expressway is completed, it is16.5km away from the midpoint. What is the total length of this highway?
4. The master and the apprentice made a batch of parts together, and the apprentice made 2/7 of the total, 2 1 less than the master. How many parts are there in this batch?
5. There is a batch of chemical fertilizers in the warehouse, and 2/5 of the total amount was taken out for the first time, and less than 1/3 of the total amount was taken out for the second time. At this time, there are 24 bags left in the warehouse. How many bags are taken out twice?
6. The distance between 6.AB is1152km. A bus and a truck leave from two places at the same time. Trucks run 72 kilometers per hour, 2/7 faster than buses. How many hours did it take for two cars to meet?
7. A coat is more expensive than a pair of trousers 160 yuan, in which the price of trousers is 3/5 of that of a coat. How much is a pair of trousers?
8. There are 60 black rabbits in the feeding group, and there are more white rabbits than black rabbits 1/5. How many white rabbits are there?
9. Kindergarten wants to dig an 80-meter-long sewer. On the first day, 1/4 of the total length was dug, and on the second day, 1/2 of the total length was dug. * * How many meters have you dug in two days? How many meters are left?
Answer:
1, analysis: 1/2 and 5 barrels have been used, leaving 30%. It can be understood that the percentage of 5 barrels is 1-1/2-30% (1/2 and 30% are removed from the unit1), so the formula is: 5 ÷ (1-1/.
2. Analysis: 7/ 10 is truncated for the first time, and the remaining 1/3 is truncated for the second time (the unit of 7/ 10 in the title is "it", that is, a steel pipe is 10m, 1/3. Therefore, it is necessary to unify the unit 1, that is, all of them are converted into several fractions of this steel pipe. Obviously, "7/ 10 first cut-off" does not need to be converted. The key point is that "the remaining 1/3 after the second cut" is converted into several fractions of the steel pipe cut for the second time, and this problem is solved.
The remaining 1/3 (i.e. 1-7/ 10) was cut off for the second time, i.e.1× (1-7/10) ×1.
So the score corresponding to 10 is
The unit 1 subtracts the score of the first cut unit 1, and then subtracts the score of the second borrowed unit.
The formula is: (1-7/10) ×1/3 =110.
10÷( 1-7/ 10- 1/ 10)
= omit one's own calculation
3. After 2/3 of the expressway is completed, it is16.5km away from the midpoint. What is the total length of this highway?
Analysis: According to the condition of "after completing 2/3 of the total length, it is from the midpoint 16.5km", 2/3 has exceeded the midpoint 1/2, so it is understandable to draw a line segment diagram, and the ` score corresponding to 16.5km is 2/3-1/.
So the formula is 16.5(2/3- 1/2).
4. The master and the apprentice made a batch of parts together, and the apprentice made 2 1 less than the master. How many parts are there in this batch?
Analysis: The question "Apprentices earned 2/7 of the total, 2 1 less than the master" means that the master earned the number of apprentices (2/7 of the total) plus 2 1.
The apprentice (2/7 of the total number) and the master (2/7 of the total number plus 2 1) * * made these parts, which is the unit of1.
It can be understood that the percentage of 2 1 part is 1-2/7-2/7.
So the formula is 2 1÷( 1-2/7-2/7).
5. There is a batch of chemical fertilizers in the warehouse, and 2/5 of the total amount was taken out for the first time, and less than 1/3 of the total amount was taken out for the second time. At this time, there are 24 bags left in the warehouse. How many bags are taken out twice?
Analysis: How many bags do you want to find twice? You must first know the unit 1, that is, what is the total? So 1 unit what is the total amount of this batch of fertilizer?
By analyzing the meaning of the question and finding out the quantity and its corresponding score, it is easy to find out the unit of 1.
The first time (2/5 of the total), the second time (1/3 of the total is missing 12 bags), and there are 24 bags left.
This means that the corresponding scores of 12 bags and 24 bags are 2/5 removed from 1 and 1/3 removed.
So the formula is (1 2+24) ÷ (1-2/5-1/3), but this is the unit of1,and the total number of this batch of fertilizers is 135 bags.
Two more times. How many bags did you take out?
135× 2/5+135×1/3-12 = 87 (package) (to write the detailed process)
6. The distance between 6.AB is1152km. A bus and a truck leave from two places at the same time. Trucks run 72 kilometers per hour, 2/7 faster than buses. How many hours did it take for two cars to meet?
Analysis: from the meaning of the problem to the quantitative relationship: the sum of total distance-speed = meeting time
The total distance is known as 1 152km.
The sum of speeds is the sum of the speeds of trucks and buses. It is known that the speed of the truck is 72km/h, so it is very important to find out the speed of the bus first (in the sentence "The truck speed is 72km/h, which is 2/7 faster than the bus", the speed of the bus is 1, so the speed of the bus is 72 ÷ (1+2).
So the speed of the train and bus is 72 ÷ (1+2/7) = 56 km/h.
1 152(72+56)= 9 (hours)
This question is a classic, so we must understand it.
7. A coat is more expensive than a pair of trousers 160 yuan, in which the price of trousers is 3/5 of that of a coat. How much is a pair of trousers?
Analysis: There are many solutions to this kind of problem, as long as the reasonable answers are consistent.
We turn such questions into comparative ideas to answer. From "the price of trousers is 3/5 of that of coat", we can know that the ratio of coat to trousers is 5:3, and a coat is more expensive than trousers 160 yuan, that is, the number of copies corresponding to 160 yuan is (5-3), so we need to have one copy first and then three copies of trousers.
The formula is 160÷(5-3)×3=240 (yuan).
Of course, this kind of problem can also be solved by fractional ideas and equations.
Solution: Let the price of a coat be X yuan (finally, let me explain why the price of a coat is X yuan instead of the price of a pair of pants asked in the question? )
According to the quantitative relationship: the price of a coat-the price of a pair of trousers = 160, list the equations.
X - 3/5x？ = 160
Solve x=400
The price of trousers is 3/5x=400×3/5=240 (note that there is no unit here, why? We often say that it is not explained here)
There may be other ideas, I hope I can share them with you. Reasonable is right.
8. There are 60 black rabbits in the feeding group, and there are more white rabbits than black rabbits 1/5. How many white rabbits are there?
Answer: 72.
9. Kindergarten wants to dig an 80-meter-long sewer. On the first day, 1/4 of the total length was dug, and on the second day, 1/2 of the total length was dug. * * How many meters have you dug in two days? How many meters are left?
Answer: Two days * * * Digging: 60 meters
Remaining: 20m.
Questions and Answers on Classical Application of Mathematics in Primary Schools 2 1. There are 25 baskets of oranges in the supermarket, and 65 baskets are brought in. Later, 40 baskets were sold. How many baskets of oranges are there in the supermarket?
25+65-40
=90-40
=50 (basket)
2. The kindergarten held a celebration on June 1 day. I bought 600 balloons and used 260 red balloons and 190 yellow balloons. How many balloons are left?
600-260- 190
=340- 190
= 150 (piece)
3. Mom bought 56 meters of cloth with 100, 12 meters for bed sheets and 27 meters for clothes. How many meters are left?
56- 12-27
=44-27
= 17 (m)
In order to order 800 kites, 286 kites were made in the first week and 327 kites were made in the second week.
(1) How much is left unfinished?
800-286-327
=5 14-327
= 187 (only)
(2) What other questions can you ask?
How much did * * * earn in two weeks?
286+327=6 13 (only)
5. Class I: 184 mineral water; Yes: 240
Category 2: 236 mineral water; Can: 169
Category III: 145 mineral water; Yes: 246
(1) How many mineral water bottles did Class One and Class Two collect?
184+236=420 (pieces)
(2) How many cans did Class Three collect than Class Two?
246- 169=77 (piece)
(3) What other questions can you ask?
Example: How many mineral water bottles have Class One and Class Two collected?
You must answer continuously.
(Just make some amendments according to (1) and (2) above. Don't ask complicated questions, it's easy to make mistakes. )
6. The thickness of a Chinese book is about 8 mm. How many millimeters are five such books? How many centimeters is it?
8X5 = 40mm
40mm = 4cm
7. Xiaohong's height 120 cm, and her mother's height 165 cm. How many centimeters does Xiaohong grow to be as tall as her mother?
165- 120=45 (cm)
8. A rope is 24 meters long. How many skipping ropes can you make every 4 meters?
24÷4=6 (root)
9. Xiaoming is 136 cm tall, the refrigerator is 64 cm taller than Xiaoming, and the refrigerator is 25 cm shorter than the door.
(1) What is the height of the door?
136+64-25
=200-25
= 175 (cm)
(2) What other questions can you ask?
How high is the refrigerator?
136+64=200 cm
10, 288 yuan for bicycles and 245 yuan for fans. Mom has 600 yuan money. Are these two enough?
288+245=533 yuan.
600 & gt533
A: These two are enough.
1 1, the theater has 500 seats, the first-year students 197, and the second-year students1.
(1) Can the cinema accommodate two classes of movies at the same time?
197+20 1=398 (person)
398 & lt500
A: The cinema can accommodate two classes of movies at the same time.
(2) If there are vacancies, how many seats are left?
500-398= 102 (piece)
12. The store sold 340 bags of rice, 54 more bags of flour than rice. How many bags of flour were sold?
340+54=394 (bag)
13, the washing machine is 568 yuan, which is more expensive than the tape recorder. 280 yuan, how much is the tape recorder?
568-280=288 (yuan)
14, Xiaodong jumped 140 cm in the standing long jump, Xiaohua jumped 30 cm more than Xiaodong, and Xiao Qiang jumped 38 cm less than Xiaodong.
(1) How many centimeters did Xiaohua jump?
140+30= 170 (cm)
How many centimeters did Xiao Qiang jump?
140-38= 102 (cm)
15, the third grade donated 435 yuan, the fourth grade donated more 78 yuan than the third grade, and the fifth grade donated less 27 yuan than the fourth grade.
(1) How much did the third and fourth grades donate?
435+78+435
=5 13+435
=948 (yuan)
(2) How much did the fifth grade donate?
435+78-27
=5 13-27
=486 (yuan)
16, 6. Today is Children's Day, and the students are having a holiday in the paper crane. Xiaohua folded 203 paper cranes, Xiaohong folded 47 more than Xiaohua, and Xiao Li folded 20 less than Xiaohua.
How many paper cranes did Xiaohong fold?
203+47=250 (only)
(2) How many are there in Dayu Xiaoli?
203-20= 183 (only)
203+ 183≈400 (only)
200 200
17. There are 496 girls in bright primary school, with 64 more boys than girls. How many boys are there? How many people are there in kindergarten one?
496+64=560 (person)
496+560= 1056 (person)
18. There is a barrel of oil. The first time it was poured out was 125 kg. The second time it was poured out, it was 30 kilograms less than the first time. How many kilograms did you pour twice?
125-30+ 125
=95+ 125
=220 kg
19. There are 200 red balloons in the store, and there are 50 yellow balloons in the red balloon. How many balloons are there in a box?
200-50+200
= 150+200
=350 (pieces)
20. There are 300 story books in the kindergarten library, and 228 have been lent out. The rest of each class is divided into 9 books. They can be divided into several classes.
(300-228)÷9. Don't remove the brackets in the comprehensive formula.
=72÷9
=8 (pieces)
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