Q6 Grade about the application of the ratio, than the application of the problem solving skills of t

It's very simple, you have to think about it yourself, don't ask others as soon as you come up, which is not conducive to the cultivation of independent thinking ability. I really can't think of another question.

1. The sum of the edge length is 76, then length + width + height = 76 4 = 19. and length: width: height = i.e. 4:10:5, so.

Length = 4, width = 10, height = 5, area = 220

2. I don't know if you have learned to understand the system of equations, it is easy to use the system of equations, and it is very wordy if you don't use it. The answer is three.

Class Communist. There is a problem with the topic.

1.Compare the length to the width first. The ratio of width and height is even the ratio.

4:10:5 (will this be, that is, find the least common multiple of the middle two, and then expand them at the same time), and then distribute them proportionally, length = 76 4 19 = 16 The same width is 40 and the high is 20

16 40 20 This is the volume.

16 40+16 20+40 20) 2 This surface area I don't know what you want.

2.The problem is that people calculate that it is a decimal.

1 。Then the ratio of length, width to height is: 2:5:

The surface area is (4*10+10*5+4*5)*2=220 square centimeters2One = (two + three) * 1 3 then 3 one = two + three.

Two = (one + three) * 1 2 then 2 two = one + three.

3 one = two + 52

2 two = one + 52

But I can't solve it, is there a problem with the question?

76 4 divided by 2 + 5 times 2 is long, and the next thing should be.

In fact, the methods and ideas for solving the average score problems, normalization problems, and fraction application problems that I have learned before are the same. In particular, ratios and fractions are inextricably linked, and the application problems of ratios can be completely transformed into fraction application problems to solve.

For example, 2:3 is 2 parts more than 3 parts, which can be 4 and 6, 6 and 9.

Encounter difficulties, such as: A and B two garment factories in December production ratio of 6:7, unit price ratio of 11:

10. The total output value of the two factories is 81.6 million yuan. How many thousand yuan is the output value of the two garment factories?

Solution: The output value of factory A: the output value of factory B = (unit price of A x quantity of A) :(unit price of B x quantity of B) = (11x6) :(10x7) = 33:35.

8160 (33+35)=120 (10,000 yuan), 120x33=3960 (10,000 yuan), 120x35=4200 (10,000 yuan).

Column equation solution application steps:

1. Practical problems (review the problem, clarify all known and last known conditions and quantitative relationships).

2. Let the last known number (generally set directly, sometimes indirectly), and use the algebraic formula of the last known number to represent all the last known quantities.

3. Find the equation of the equivalence off.

4. Solve the equation and find other final conditions.

5. Test (test whether it is the solution of the original equation and whether it conforms to the practical significance).

6. Answer.

1. When Xiao Ming reads a book, the ratio of the number of pages read to the number of pages he has not read is 5:4. If you read another 27 pages, the ratio of the number of pages read to the number of pages not read is 2:1.

How many pages is there in this book + Analysis and Answer: Since the ratio of the number of pages read to the number of pages unread is 5:4, then the number of pages read accounts for 95 of the total number of pages in the library, and if you read another 27 pages, the ratio of the number of pages read to the number of pages not read is 2:

1, at this time, the number of pages read accounts for 32 of the total number of pages, then the corresponding score of 27 pages is 32-95 = 91, then the book has a total of 27 91 = 243 (pages).

2. Six (1) The ratio of the number of boys to the number of girls is 5:4, and it is known that there are 3 fewer girls than boys, how many people are in the class + Analysis and Answer: Because the ratio of the number of boys to the number of girls is 5:

4, can be understood as 5 copies of boys, 4 copies of girls, then girls are 5-4 = 1 less than boys, then 1 part is 3 people, the whole class has a total of 5 + 4 = 9 (parts), then there is a total of 3 9 = 27 (people).

3. For example: 2:3, that is, 2 parts to 3 parts, can be 4 and 6, 6 and 9.

Encounter difficulties, such as: A and B two garment factories in December production ratio of 6:7, unit price ratio of 11:

10. The total output value of the two factories is 81.6 million yuan. How many thousand yuan is the output value of the two garment factories?

Solution: The output value of factory A: the output value of factory B = (unit price of A x quantity of A) :(unit price of B x quantity of B) = (11x6) :(10x7) = 33:35.

8160 (33+35)=120 (10,000 yuan), 120x33=3960 (10,000 yuan), 120x35=4200 (10,000 yuan).

Application of ratio: Focus: The solution of the distribution problem according to a certain ratio.

Difficulty: Establish the relationship between the quantity of each part and the total amount.

1. The significance of distribution according to a certain ratio: In industrial and agricultural production and daily life, it is often necessary to distribute a quantity according to a certain ratio, and this distribution method is usually called proportional distribution.

2. The solution to the problem of distribution according to a certain ratio: the problem of distribution according to a certain ratio should first find out how many parts of the total amount are divided, then find out the number of parts in the total and express it with fractions, and then use fraction multiplication to solve it; Or use the method of average score to find the specific quantity of each part, and then find out the amount of each part.

3. The application of distribution according to a certain ratio:

Knowing the total amount and the ratio between the two parts, find the parts.

Knowing the relationship between a partial quantity and the ratio between two partial quantities, find the total amount.

Knowing the relationship between a partial quantity and the ratio between two partial quantities, find another partial quantity.

Knowing the difference between two partial quantities, find the partial quantity or the total amount.

(4 5-7 12) = 46 and 2 13 grams. And.

6+5) 6=480 people. Schoolboy.

480 16 13 = 390 people. The original schoolgirl.

880-480 = 400 people. Later girls.

400-390 = 10 people. Transferred girls.

3 8-1 6) = 284 pages. Total number of pages.

3 10-1 5) = 40 tons.

9 15-2 4) = 300 pcs. And.

300 (9+4+2) 4=80. Original B.

300 (2+1+1)=75. B after the change.

80-75 = 5 pcs. The number of B to C.

Fill in the blanks: 1. A batch of goods is allocated to three teams A, B and C according to 2 3 4, and this batch of goods has a total of ( ) copies, including ( ) copies of team A, ( ) copies of team B ( ), team C ( ) ( ) team A of this batch of goods ( ) B team of goods ( ) C team of this batch of goods ( ) of C ( ).

2. There are 20 boys and 30 girls in class 6 (1), and the ratio of boys to girls is ( ) The ratio of boys to the total number is ( ).

3. A car has traveled 360 kilometers in 6 hours, and the ratio of the distance and time traveled by the car is ( ) The ratio is ( ) The ratio of the time and distance traveled by the car is (, and the ratio is ( ).

5. The sum of the three numbers A, B, and C is 60, and the ratio of the three numbers A, B, and C is 3 2 1. The three numbers A, B, and C are ( ).

6. The quotient of the number A divided by the number B is, and the simplest integer ratio of the two numbers of A and B is (

Problem solving 1. A total of 36 tons of sand and stone, the ratio of sand to stone is 1 8, how many tons of sand and stone are there?

2. The circumference of a rectangle is 88cm, and the ratio of length to width is 4 7. How many centimeters is the length and width of a rectangle? What is the area?

3. The ratio of the number of internal angles of a triangle is 3 2 1, find the degrees of each angle, and say what kind of triangle it is?

4. The ratio of the number of locust trees and poplars in the park is 2 3, there are 40 locust trees and poplars, and how many willows and poplars are there?

5. There are 60 skipping ropes in the physical education room, which are assigned to two classes A and B according to the number of people, there are 42 people in class A and 48 people in class B.

1. The circumference of a rectangle is 24 cm, and the ratio of length to width is 2:1.

2. The sum of the edges of a cuboid is 96 cm, and the ratio of length, width and height is 3 2 1, what is the volume of this cuboid?

3. The sum of the edges of a cuboid is 96 cm, the height is 4 cm, and the ratio of length to width is 3 2, what is the volume of this cuboid?

4. There are 42 students in a computer interest group in a school, of which the ratio of male and female students is 4 3, how many male students are there?

5. There are two baskets of fruits, the fruit in the first basket weighs 32 kilograms, after taking out 20 from the second basket, the weight ratio of the two baskets of fruits in A and B is 4:3, how many kilograms of the original two baskets of fruits are there?

6 To make a 600g bean paste bag, you need flour The ratio of red beans to sugar is 3:2:1, how many grams of flour do you need for red beans and sugar?

7. Xiao Ming read a story book, read 1 9 of the whole book on the first day, read 24 pages on the second day, the ratio of the number of pages read in two days to the number of remaining pages is 1:4, how many pages are there in this book?

8. The ratio of the three inner angles of a triangle is 2:3:4, what are the degrees of these three inner angles?

Or so. Let the length of the armor be 3x, then the width of the armor is 2x, the length of the armor is 7y, and the width of the armor is 5y, then 3x+2x=7y+5y5y=12yx=12y x y=12 5

The area of A is 6x 2, B 35y 2 A: B = 6x 2 35y 2 = 6 35x144 25 = 864 875

The question is wrong, the length and width of the square should be equal, so there is no solution to this problem.

There are two in the bottom corner.

Top Angle Bottom Angle Bottom Angle = 2 3 3

Top angle = 180° 2 (2+3+3) = 45° Base angle = (180-45°) 2=

The sum of the inner angles of the triangle is 180, and because it is isosceles, it is 2:3:3

So the top angle is 45, and the bottom angle is two.