2, 4.2×2.5 is 4.2 ().

(3) It is known that the product of two factors is 4.2, one of which is 7 and the other is ().

④ 0.8 enlargement 100 times is (), and () reduction 10 times is 0.87.

5], 2.7 accurate to the percentile is (), keep three decimal places is ().

[6], 0.6 hectares = () square meters 0.25 hours = () minutes.

Once, the periodic cross section is 0.247247 ... is (), and two decimal places are (), which can be written as () in a simple way.

⑻ The product of1.8× 3.02 has () decimal places.

Levies, 1.7÷0.5 When the quotient is 3, the remainder is ().

⑽ When multiplying two factors, if one factor is amplified by 2 times and the other factor is amplified by 4 times, the product is amplified by () times.

⑾, 3.5 1, 3.505 and 3.505, the largest is () and the smallest is ().

⑿ If 4 ÷ A < 4, then A must be ().

[13]. After the decimal point is shifted one place to the right, the sum with the original decimal point is 12. 1, and the original decimal point is ().

Second, judge. (8 points)

(1) Add 0 or remove 0 after the decimal point, and the size of the decimal point remains unchanged. ( )

(2) Fractional division has the same meaning as integer division. ( )

(3), 3.142142142 are pure cyclic decimals. ( )

(4), a non-zero natural number multiplied by a decimal, the product must be less than this number. ( )

5] When calculating decimal addition, subtraction, multiplication and division, the decimal points must be aligned. ( )

[6] The arithmetic of integer multiplication is also applicable to fractional multiplication. ( )

At one time, similarity number 7.33 and similarity number 7.330 were equal in any case. ( )

Existence, cyclic decimal must be infinite decimal, and infinite decimal must also be cyclic decimal. ( )

Third, choose. (8 points)

(1), dividend unchanged, divisor decimal point shifted to the right by two places, quotient ().

A, expand 100 times b, reduce 100 times c, unchanged.

(2) The quotient of 28 ÷11is ().

A, pure cyclic decimal b, mixed cyclic decimal c, finite decimal

(3) If the decimal point of a decimal moves two places to the left, the number will be ().

A, expand by 2 times b, reduce by 100 times c and expand by 100 times.

(4), the following accurate to 0.0 1 is ().

a、0.6938≈0.694 B、8.045≈8.0 C、9.6954≈9.70

5], the largest number of the following formulas is ().

a、6.98× 1 B、6.98×0.98 C、6.98× 1.98

[6], a number expanded 42 times is 78.2, and the formula for finding this series is ().

a、78.2×42 B、78.2÷ 42 C、42 \78.2

Once, the car is 0.05 hours 1.5 kilometers, and the average number of kilometers per hour is ().

a、 1.5÷0.05 B、0.05÷ 1.5 C、 1.5÷ 1

(8) The number of boys in Class A accounts for half of the total number of students in Class A, and the number of boys in Class B accounts for half of the total number of students in Class B. The number of boys in Class A and Class B is compared ().

A, equal b, unequal c, uncertain

Fourth, calculation.

(1), oral calculation. (5 points)

1.5×9+ 1.5= 0. 15×24= 6.3÷0.7=

3.2×0.5×0= 1.6÷0.4÷0.5=

(2) Use vertical calculation. (4 points)

5.8×0.325 78.58÷3.7 (the number is kept to two decimal places)

(3), calculation. (Simplification that can be simplified) (12 points)

( 16.5×3+7.5×3)÷6 1.25×0.84×80-84

4.75+50÷8×0.4 9.56×8+9.56×2

(4) Column calculation. (8 points)

1, 8 times a number is 7.5, how much is half of it?

What is the difference quotient between 2.8.2 and 1.2 divided by the sum of 2.5 and 1.5?

Fifth, the application problem. (35 points)

(1), how many kilometers does a car travel per hour on average when it travels 35 kilometers for 0.5 hours?

2, a workshop to process 9000 parts, known processing for 5 days, an average of 800 pieces a day, the rest of the requirements for 4 days to complete, the average number of pieces a day?

(3), a batch of goods, each batch of 5.5 tons, 10 times can be shipped out, if you want to ship out 8 times, how many tons will be shipped out on average each time?

(4) In Xiaoming's mid-term exam, the average number of words is 97, and the average number of natural subjects is 97.5. How many points did Xiaoming get in the natural exam?

A professional household keeps 3500 chickens and ducks. It is known that the number of ducks is 2.5 times that of chickens. How many chickens and ducks are there?

The canteen brought 7000 Jin of rice, 2.5 times less than flour. How many kilograms of flour were shipped?

On one occasion, two cars, A and B, walked back from AB, with a distance of 20 kilometers. Party A travels 80 kilometers per hour, which is twice the speed of Party B. How many kilometers are the two cars apart after five hours? 1 There are X girls in the school science and technology group, and the number of boys is three times that of girls. How many male students are there? How many boys and girls are there? How many more boys than girls?

The school bought three new books *** 100. Among them, literature and art books are three times as many as science and technology books, and picture books are eight times less than half as many as science and technology books. How many books did you buy each of these three books?

1. A cuboid bunker is 4m long, 2m wide and 0.5m deep. If the yellow sand weighs 1.4 tons per cubic meter, how many tons does it weigh?

2. It is known that a rectangular tin tank with a length of 18 decimeter and a width of 10 decimeter can hold 1620 liters of water. How deep is this tank?

3. The cuboid plastic box containing the liquid medicine is 0.6m long, 0.25m wide and 0.5m deep. If you put the whole box of medicine into a small bottle with a capacity of 400ml each, how many bottles should this box contain at least?

4. A cubic billet is 6 cm long and forged into rectangular steel with a cross section of 3 cm long. How many meters is steel?

5. A cuboid oil drum with a bottom area of 18 square decimeter can hold 43.2 kilograms of oil. If the weight of each liter of oil is 0.8 kg, what is the height of the oil drum?

6. In a glass jar with a length of 25cm and a width of 20cm, there is a cubic iron block with a length of10cm. At this time, the water depth is 15 cm. If this iron block is taken out of the jar, how many centimeters is the water depth in the jar?

7. A cuboid fuel tank with a square bottom and a side length of 6 decimeters measured from the inside. It contains 144 liters of oil. As we all know, the depth of the oil inside is half that of the oil tank. How many decimetres is this oil tank?

8. One room 1200 wooden floor, 40 cm long, 20 cm wide and 2 cm thick. How many square meters is this room? How many cubic meters of wood does it take to spread out this room?

9. A section of rectangular steel, with a length of1.6m and a cross section of 4cm square. It weighs only 7.8 grams per cubic centimeter. How much does this square steel weigh?

10. Make an uncovered cuboid oil drum with iron sheet. The length and width are 4 decimeters and the height is 6 decimeters. How many square decimetres is the iron sheet? Put gasoline in a barrel, and each liter of oil weighs 0.82 kg. How many kilograms of gasoline can this barrel hold?

1 1. Forge a cubic billet with a length of 0.6 meters into rectangular steel with a cross section of 0.09 square meters. How long is forged steel? (Equation solving)

12, a cuboid glass tank, measuring 40 cm long and 25 cm wide from the inside, and the water depth in the tank is 12 cm. After a stone is immersed in water, the water surface rises to 16 cm, and the volume of the stone is found.

13. Make 12 cuboid iron chimneys, each section is 2m long, 4m wide and 3m high. How many square meters of iron do you need at least?

14. The floor of Xiao Min's room is rectangular. It is 5 meters long and 3 meters wide, and has a 2 cm thick wooden floor. How many cubic meters of wood do you need at least?

15, a coal truck, viewed from the inside, is 2.5m long and1.8m wide, and the loaded coal is 0.6m high, with an average weight of1.5t per cubic meter. How many tons of coal does this truck carry?

16. rectangular iron drum without cover, with square bottom, 4m side length and 1m height. How much iron does it take to make such a barrel? How many liters of water can this barrel hold?

17. The stadium is paved with 37.5 cubic meters of cinder on a straight runway with a length of 100 meter and a width of 7.5 meters. How thick can cinder be spread?

18, rectangular children's swimming pool, 40m long,14m wide and1.2m deep. How many square bricks with an area of 16 square decimeter should be pasted on the wall and bottom of the pool now?

19, cuboid container, bottom area 16 square decimeter, water height 6 decimeter. Now put an iron block with a volume of 24 cubic decimeters. How high is the water surface at this time?

20. Stack 2 100 cubes with a side length of 1 cm into a cuboid. Its height is 10 cm, and its length and width are greater than its height. What is the circumference of its bottom?

2 1, rectangular iron sheet, 32 cm long, cut a square with a length of 4 cm at its four corners, then fold it and weld it into a rectangular iron sheet box without a cover. It is known that the volume of this iron box is 768 cubic centimeters. What is the area of this iron?

22. The area of a rectangle is 24 cm, and its length and width are all whole centimeters. How many kinds of rectangles are there?

23. Class 5 (1) has no more than 50 students. When studying in groups, according to the different teaching contents, they can be divided into 3 people in each group, 4 people in each group, 6 people in each group and 8 people in each group. All kinds of points are just finished. There may be () students in this class or () students.

24. Party A, Party B and Party C borrow books from the library. Party A comes every six days, Party B comes every eight days and Party C comes every nine days. If we meet in the library on March 5, when will we go to the library next time?

25. Gardeners planted a tree every 4 meters on both sides of a highway, and planted 74 trees in a row. Now it's time to plant a tree every 6 meters. So, how many trees don't need transplanting?

26. Uncle Zhang sold fruit all day. When counting money at night, he found that a stack of banknotes in his hand was all two yuan and five yuan. Zhang divided the pile of money into two piles with equal amounts. In the first pile, the amount of five yuan and two yuan is equal, and in the second pile, the number of five yuan and two yuan is equal. Do you know how much money this stack of bills has at least?

27. The fifth-grade students in bright primary school are divided into groups of 786, all of whom have just finished their studies. How many students are there in Grade Five?

Is that enough?