The sixth grade math proportional test is a representative one.

Proportional exercise

First, think about it and fill it out.

1, in 4: 7 = 48: 84, 4 and 84 are proportional (), and 7 and 48 are proportional ().

2.4 :5 = 24 ÷( )= ( ): 15

3. The diameter of the big circle is 4cm, and the diameter of the small circle is 2cm. The simplest integer ratio of the circumference of the big circle and the small circle is (), and the simplest integer ratio of the area is ().

4. The divisor of12 is (). Choose four of them to form the ratio of ().

5. In proportion, the two external terms are reciprocal, one is 16 and the other is ().

Second, please be a small referee. (9 points)

1, the formula composed of two ratios is called proportion. ( )

2. Enlarge the former term of a ratio by 2 times and reduce the latter term by 2 times, and the ratio of this ratio remains unchanged. ( )

3. If 8A = 9B, then b: a = 8: 9. ( )

4.2, 3, 4 and 5 can form a proportion. ( )

5. In the proportion, the quotient of two outer products divided by two inner products is 1. ( )

Third, choose the serial number of the correct answer and fill it in brackets.

1. Two ratios in the following group () cannot form a ratio.

A, 8:7 and 14: 16 B, 0.6:0.2 and 3: 1 C, 19: 16 and 10:9.

2. On the clock face, the ratio of the rotation speed of the minute hand and the hour hand is ().

①60: 1 ②360: 1 ③ 12: 1

3. Because 3a=4b, ().

①a∶b = 3∶4②a∶4 = 3∶b③b∶3 = a∶4④3∶a = 4∶b

Fourth, write the following solution than the solution basis.

85∶X=20∶4 20X=340

According to, 20X=85×4.

According to, X=340÷20

Verb (abbreviation for verb) solution ratio

x: 14 = 6:28 0.25∶x = 7.5∶ 15×8 = 3:0.5

8∶X = 3/4∶ 1/2 6.5∶X = 3.25∶4 0.9∶0.03 = 30∶X

V. Application problems:

1. The ratio of male to female in the choir is 5: 7, among which 25 are girls. How many boys are there in this choir?

1, the speed ratio of a bus and a car is 1:2. If the speed of the car is 120km, what is the speed of the bus?

2. The actual height of Garden Community 1 Building is 45 meters, and the ratio of its height to the model height is 500: 1. What is the height of the model?

3. Wash the fruit with detergent with a dilution of 1: 1000. There are 3000 milliliters of water now. How many milliliters of detergent should I add?

Six, use the following four numbers to form a proportion, and see how many can be formed?

3 4 6 8

Question training form

1. The food processing factory is going to bottle a batch of newly brewed vinegar and transport it to the store.

Capacity per bottle/ml 250 500 750 1500

Quantity/bottle 1200 600 400 200

Is the capacity of each bottle inversely proportional to the number of bottles filled? Why?

It is known that x and y are inversely proportional. Fill in the following table according to the conditions in the table.

x 2 1/5 40

y 5 0. 1 5/6

3. Choose (put the serial number of the correct answer in brackets).

(1) In the process of proportional change of two quantities, one quantity shrinks and the other quantity ().

A. Enlarge B. Reduce C. Keep the same

(2) The law that two quantities are in direct proportion when changing is that their () is unchanged.

A. and B. Difference C. Product D. Quotient

(3) The perimeter of a square and its side length ().

A. in direct proportion to ...

(4) In a pile of coal, the burnt tonnage and the remaining tonnage ().

A. in direct proportion to ...

(5) Two quantities in inverse proportion, one is amplified and the other is ().

A. expansion B. contraction C. unchanged

(6) The law of the inverse ratio of two quantities is that their () is certain.

A. and B. difference C. product D.

(7) The total number of words in a book is certain, and the number of words and pages per page is ().

A. inversely proportional

(8) The area of a triangle is constant, and its base and height ().

A. inversely proportional

Second, judge whether the two quantities in each of the following questions are inversely proportional, and why?

(1) The unit price of apples is fixed, and the quantity and total price of apples are purchased.

The speed, distance and time of the ship are constant.

(3) The number of rice weaves per hour is fixed, the total number of rice weaves and the time.

(1) The total number of trees planted is fixed, and the number and number of trees planted by each person. ( )

(2) The speed and time required for Uncle Li to ride his bike from home to the factory. ( )

(3) Huarong Road did 12 math problems, completed problems and unfinished problems. ( )

(4) The area of a rectangle remains the same, and so does its length and width. ( )

(5) Kobayashi takes some money to buy exercise books, the unit price and the quantity purchased. ( )

(6) The total amount of seeds is fixed, the sowing amount per hectare and the number of hectares sown.

(7) The total amount of coal burned is certain, the daily amount of coal burned and the number of combustible days.

(8) The total production of TV sets is fixed, and the number of TV sets produced every day and the number of days of use are fixed.

(9) A parallelogram has a certain area, a bottom and a height.

The area and radius of a circle are out of proportion? Why?

1, the area of the circle is proportional to the radius of the circle. ( )

2. The area of a circle is proportional to the square of its radius. ( )

The area of a circle is proportional to the square of the circumference. ( )

The area of a square is proportional to the length of its sides. ( )

The circumference of a square is in direct proportion to the length of its side. ( )

6. When the area of a rectangle is constant, the length and width are inversely proportional. ( )

7. When the perimeter of a rectangle is constant, the length and width are inversely proportional. ( )

8. When the area of a triangle is constant, the base is inversely proportional to the height. ( )

9. When the trapezoidal area is constant, the sum of the upper and lower bottoms is inversely proportional to the height. ( )

10, the circumference of a circle is directly proportional to the radius of the circle. ( )

Judgment of proportional relationship

1, constant speed, distance, time () ratio.

A certain ratio of distance, speed and time ().

Time is fixed, and distance and speed are proportional to ().

2, a certain work efficiency, the ratio of total work and working hours ().

Working hours are fixed, and the ratio of working efficiency to total work ().

The total amount of work is fixed, and the ratio of work efficiency to working hours ().

3. When the total price is fixed, the ratio of unit price to quantity is ().

A certain quantity, unit price and total price () ratio.

The unit price is fixed, and the ratio between quantity and total price ().

4, a certain yield per hectare, the ratio of the total output and the number of hectares ().

The number of hectares is fixed, and the ratio of output per hectare to total output is ().

The total output remains unchanged, and the ratio of output per hectare to the number of hectares () remains unchanged.

5, a certain number of copies, the ratio of each copy to the total number of copies ().

Each share is fixed, and the ratio of the number of shares to the total number of shares is ()

The total number is fixed, and the ratio of each copy to the number of copies ()

6, the quotient is certain, the ratio of divisor and dividend ().

The divisor is fixed, and the ratio of quotient to dividend is ().

The divider is fixed, and so is the ratio of divisor to quotient ().

7, product, the ratio of two factors ().

One factor is constant, and the other factor is proportional to the product ().

8, and a certain, () ratio of two addends

One addend is fixed, and the other is proportional to the sum ().

9, the difference is certain, and reduced to the proportion of the minuend ().

The reduction is certain, and the ratio of the sum of the minuets to the difference ().

The minuend is definite, and the ratio of the sum to the difference of the minuend is ().

10, the ratio of the last item in the preceding paragraph to the ratio ().

The ratio of the former term to the latter term () is constant.

The latter term is definite, and the former term is directly proportional to the ratio ().

1 1, the fractional value is fixed, and the numerator is proportional to the denominator ().

The denominator is certain, and the fractional value is proportional to the numerator ().

The numerator is definite, and the fractional value is proportional to the denominator ()

12, in a rectangle, the length is certain, and the area is proportional to the width ().

A certain ratio of width, area and length ().

A certain ratio of area, length and width ().

The perimeter is constant, and the aspect ratio is ()

A certain ratio of length, perimeter and width ().

A certain ratio of width, perimeter and length ().

13. In a parallelogram, the base is constant, and the ratio of area to height is ().

A certain ratio of height, area and bottom ().

Fixed area, bottom-to-height ratio ()

14, in a triangle, the bottom is certain, and the area is proportional to the height ().

A certain ratio of height, area and bottom ().

Fixed area, bottom-to-height ratio ()

15, in a square, the ratio of side length to perimeter ().

Ratio of area to side length

16, in a circle, the ratio of area to radius ()

Ratio of perimeter to radius ()

Ratio of diameter to radius ()

Ratio of diameter to area ()

17, in a cuboid, the bottom area is constant, and the volume is proportional to the height ().

The volume is constant, and the ratio of bottom area to height () is constant.

A certain height, the ratio of bottom area to volume ()

18, on the scale, the scale is certain,

The ratio of the distance on the map to the actual distance ()

The distance on the map is fixed, and the scale is proportional to the actual distance ()

The actual distance is constant, and the proportion is proportional to the distance () on the map.

19. When soybean is used to extract oil and the oil yield remains unchanged,

Ratio of oil weight to soybean weight ().

The weight of soybean is constant, and the ratio of oil weight to oil yield is ()

When the weight of oil is constant, the ratio of soybean weight to oil yield ().

20, A × B = C, when c is constant, the ratio of a to b ().

When a is constant, the ratio of c to b ()

When Otsuichi is constant, the ratio of A to C ().

2 1, the circumference (or radius, diameter) of the wheel is fixed,

The ratio of the forward distance of the wheel to the number of revolutions ()

22, the total weight of a pile of coal, burned and the rest of the ratio of ().

23. The total distance to travel is certain, and the ratio of the distance traveled to the remaining distance ().

24, within the prescribed time, the ratio of the time to manufacture each part and the number of manufactured parts ().

25. The total number of pages in a batch of paper is fixed, and the ratio of the number of bound exercise books to the number of pages in each exercise book ().

26, each coat with a certain amount of cloth, the number of coats and the total number of meters with the ratio of cloth ().

27. The area of each brick is certain.

Ratio of total floor area to total number of bricks ()

28. The total floor space is certain.

The ratio of the area of each brick to the total number of bricks used ()

29. The weight of iron per cubic centimeter is constant.

The ratio of total weight to volume of iron ()

30, the total price and quantity of all kinds of goods () ratio.

3 1, the ratio of the number of teeth to the number of revolutions of intermeshing gears ()

32, a person's height and weight () ratio.

33, a person's age and height () ratio.

35. The total number of people must be the ratio of the number of people in each row to the number of rows ().

36. The total weight of a pile of goods is certain.

The ratio of the load of each vehicle to the number of vehicles ()

37. The side length of a cube is certain, and the ratio of its volume to its surface area is ().

38. The total length of the highway is certain.

Proportion of repaired and unrepaired ()

39. The same wire has a certain weight per meter.

Ratio of total weight to length of iron wire ()

To sum up: