Fill in the blanks. (22 points)

1. It is estimated that at the end of last century, China lost 500,000,000 tons of soil, the unit of "100 million" was () tons, the grassland in the west decreased by12,793,000 hectares, and the unit of "10,000" was () hectares. Therefore, protecting the environment and ecology is a very urgent and important task.

2.6.75: The ratio of1.8 to the simplest integer is (), and the ratio is ().

3, 2 hours = () 8.06 m3 = () m3 () m3.

4、( )÷8=0.75= =( )÷4=( )%

4. A pile of chemical fertilizer has 6 tons, which are distributed to the three production teams of A, B and C according to the ratio of 1:3:4. Team A gets (-) tons of fertilizer, and team B gets (-) tons.

The distance between Party A and Party B is 35km, and the length drawn on the map is 7cm. The scale of this map is ().

The least common multiple of 6, 24 and 54 is (), and the greatest common divisor is ().

7. The sixth grade students carried out tree planting activities, 95 trees survived and 5 trees did not survive. The survival rate is ().

8. The sum of the volumes of cylinders and cones with equal bottoms and heights is 36 cubic decimeters, so the volume of cylinders is

(), the volume of the cone is ().

9. The sum of the sides of a cube is 48 cm, its surface area is () square cm, and its volume is () cubic cm.

10, in 1.606, 1, 166%, 1.667, the maximum number is () and the minimum number is ().

1 1, the unit price is b yuan, and it should be () yuan to buy x books. 15 yuan can buy them.

() This exercise book.

2. Judgment (a "√" in brackets means right, and a "×" means wrong). (5 points)

1, the score unit is 15, and the minimum false score is 65. ( )

2. The length, width and height of a cuboid are all expanded by 3 times, and the volume is expanded by 9 times. ( )

3. If x × = y×, then x: y =:. ( )

4.A number can be divisible by B number, and B number must be the greatest common divisor of A number and B number. ( )

5. The working hours are fixed, and the time for manufacturing each part is directly proportional to the number of parts. ( )

Third, choose. (Fill in the serial number of the correct answer in brackets) (3 points)

1 and 3.496 keep two decimal places, which is about ().

①3.49 ②4.00 ③3.50

2. Typing a manuscript takes Party A 5 minutes and Party B 8 minutes, which is the simplest work efficiency ratio between Party A and Party B..

Yes (). ①5:8 ②8:5 ③ :

3. Among the following fractions, the one that cannot be converted into a finite fraction is ().

① ② ③ ④

Fourth, calculation. (35 points)

1, a number written directly. ( 10)

5.4+8= 9- 1 = 9÷ = 400÷25÷4=

3.75+ = ÷4= 6- 1.2-2.8 = × 1.5=

5.5+ 1 1.6+4.5=

2, solve the equation (9 points)

① 1-x =②38:x = 4.75:③x+x = 1.4