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Primary school mathematics problem-solving steps and methods, to be detailed!
In order to master the skills and skills of solving practical problems, we also need to master the basic methods of solving practical problems. Generally, it can be divided into comprehensive method, analysis method, graphic method, demonstration method, elimination method, assumption method, inverse method, enumeration method, etc
Several practical problems
The length of a teaching building is 80m and the width is 20m. If you want to draw the plan of this teaching building according to the scale of 1-800, how many meters is the length and how many meters is the width?
A cylindrical water pipe has an outer diameter of 32cm and a wall thickness of 1cm. The velocity of water in the pipe is 4.5m per second, which is the same as how many kilograms of water can be discharged from the pipe per second? (1 square centimeter of water weighs 1g)
A cone-shaped sand pile with a bottom area of 3.6 square meters and 2m. How high can it be installed in a sand pit with a length of 2M and a width of 1.5m?
Li Xinjia bought a house in a residential area. The following is the floor plan of her living room. The width is 4cm and the length is 3cm. There are two kinds of square bricks with side length of 3DM and 4dm available. Please choose the most suitable one. Calculate the number of blocks to be laid in Chen Mingjia's living room. (the scale is 1:200)
The length of a teaching building is 80m and the width is 20m. If you want to draw the plan of this teaching building according to the scale of 1-800, how many meters is the length and how many meters is the width?
Length = 80 / 800 = 0.1M
Width = 20 / 800 = 0.025m
A cylindrical water pipe has an outer diameter of 32cm and a wall thickness of 1cm. The velocity of water in the pipe is 4.5m per second, which is the same as how many kilograms of water can be discharged from the pipe per second? (1 square centimeter of water weighs 1g)
Internal diameter = 32-1 × 2 = 30cm
Radius = 30 / 2 = 15 cm
Water outflow per second = 3.14 × 15 × 15 × 4.5 × 100 × 1 = 317925g = 317.925kg
A conical sand pile has a bottom area of 3.6 square meters and a height of 1.2m. How high can it be installed in a sand pit with a length of 2M and a width of 1.5m?
Sand pile volume = 1 / 3 × 3.6 × 1.2 = 1.44 M3
It can hold 1.44 / (2 × 1.5) = 0.48 m high
Li Xinjia bought a house in a residential area. The following is the floor plan of her living room. The width is 4cm and the length is 3cm. There are two kinds of square bricks with side length of 3DM and 4dm available. Please choose the most suitable one. Calculate the number of blocks to be laid in Chen Mingjia's living room. (the scale is 1:200)
Actual length = 3 × 200 = 600 cm = 6 m
Actual width = 4 × 200 = 800cm = 8M
Area = 8 × 6 = 48 square meters
Specification of square brick: 3 decimeter = 0.3 meter
4 decimeters = 0.4 meters
It is more appropriate to choose the side length of 0.4 meters, because 0.4 can be divided by 6 and 8
The long direction needs 6 / 0.4 = 15 pieces
The wide direction needs 8 / 0.4 = 20 pieces
A total of 15 × 20 = 300 yuan
Distance calculation,
Read the contour map (as shown in the figure), scale 1:50000, answer the following questions. Question: the distance between village a and village B is
The scale of the map is 1:50000, that is to say, 1cm on the map represents the actual distance of 50000cm, which is 500m. We can roughly measure the distance between village a and village B on the map is about 3cm, and the actual distance is 3 times 500m, which is about 1500m
RELATED INFORMATIONS
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