1. Think carefully and sit in the right position: (20%)

1. The number of () rewritten as "ten thousand" is 95.678 million, and the mantissa after omitting "hundred million" is about ().

2. Saw the 5-meter-long steel bar into equal-length segments for 6 times, and each segment accounts for () () meters of the total length. If you saw it in half in 2 minutes, it would take () minutes in 6 minutes.

3. Observe and think:

□ and△ in the formula (1) each represent a number. Known: (△+□)×0.3=4.2, □÷0.4= 12.

Then, △ = (), □ = ().

(2) Look at the right side of the picture and fill in a letter in the brackets below to make the equation hold.

Front area () = upper area ()

4. The picture on the right shows the number of days required for Party A, Party B and Party C to complete a project independently.

Statistical chart. Please look at the picture and fill in the blanks.

Party A and Party B cooperate in this project, which can be completed within () days.

(2) First, Party A will do it for 3 days, and the rest of the project will be done by Party C, which will take () days to complete.

5.A = 2× 3× m, B = 3× 5× m (m is a natural number, m≠0), if the greatest common divisor of A and B is 2 1,

Then m is (), and the least common multiple of a and b is ().

6. Fold a rope into 5 strands and 6 strands respectively. If 5 strands are 20 cm longer than 6 strands, then the length of this rope is () meters.

7. The average of three numbers A, B and C is 70, A: B = 2: 3, B: C = 4: 5, and B number ().

8. If the decimal point of a number is moved one place to the right and then three places to the left, the new number is 34.65 less than the original number, and the original number is ().

9. With "ten thousand" as the unit, the difference between the exact number of 50000 and the approximate number of 50000 is at most ().

10. Xiaoming bought a new bottle of toothpaste with a net volume of 45 cubic centimeters. The diameter of the circular outlet of toothpaste is 6 mm He brushes his teeth once in the morning and once in the evening, and the toothpaste squeezed out each time is about 20 mm long. This bottle of toothpaste is estimated to last () days. (Take 3 as the approximate value of pi)

1 1. When the area formula of a circle is derived, the circle is divided into several equal parts and pieced together into an approximate rectangle. It is known that the length ratio of a rectangle is 6.42 cm, and the area of a circle is () cm 2.

12. A ship sails from place A to place B at a speed of 30 kilometers per hour, and then returns the same way. If the average speed back and forth is 40 kilometers, you should sail () kilometers when you return.

2. Repeated comparison and merit-based admission: (10%)

1. It is known that a× 23 = b× 135 = c ÷ 23, and a, b and c are not equal to 0, then the smallest number among a, b and c is ().

① a ② b ③ c

2. In the integer division formula with remainder, the divisor is B, the quotient is C, (both B and C are not 0), and the largest dividend is ().

① bc+b ② bc- 1 ③ bc+b- 1

3. Add 6 grams of salt 14 grams of water to the salt water with a salt content of 30%. At this point, the percentage of salt in the brine is ().

① equal to 30%; ② Less than 30%; ③ More than 30%.

4. Xiaohua wants to help her mother do the following things at the weekend: it takes 20 minutes to wash clothes with the washing machine; It takes 6 minutes to sweep the floor; It takes 10 minute to clean the furniture; It takes five minutes to dry the clothes. After reasonable arrangement, it will take her at least () minutes to finish these things.

① 2 1 ② 25 ③ 26

5. In the following categories (both A and B are not 0), the inverse ratio of A and B is ().

①a×8 = b5②9a = 6b③a× 13- 1÷b = 0④a+7 10 = b

Give all five identical gifts to three children, so that each child can get a gift. There are () different ways to give gifts.

① 3 ② 4 ③ 5 ④ 6

7. Selling a pair of shoes 140 yuan can earn 40%, and selling 120 yuan can earn ().

① 20% ② 22% ③ 25% ④ 30%

8. On the map with the scale of 1: 3000000, the distance from A to B is measured to be 5.6 cm. A car will complete the journey in two days according to the ratio of 3: 2, and the distance difference between the two days is () kilometers.

① 672 ② 1008 ③ 336 ④ 1680

9. If the height of a cone remains the same, the radius of the bottom surface will increase by 13, and the volume will increase ().

① 13 ② 19 ③ 79 ④ 169

10. A car travels from place A to place B at a speed of 50 kilometers per hour, which is 80 kilometers apart. The gasoline you bring will last for 2 hours at most. If you don't refuel halfway, in order to ensure the return trip, you should drive at most () kilometers back to the starting point.

① 20 ② 40 ③ 50 ④ 100

3. See the topic clearly and think skillfully:

(1) Writing numbers directly is fast! (8%)

1322- 199= 1.87+5.3= 2.5×2.4= 1÷ 13 - 13 ÷ 1 =

4.9×8. 1≈ 23.9÷8≈ 0.32 - 0.23 = ( ): 17 = 17

(2) Clever! (Write a simple calculation process) (12%)

2004×20022003 ( 1 15 +2 17 )× 15× 17 1 1×2 + 12×3 + 13×4 + …… + 198×99 + 199× 100

Loosen your wrist, tidy up your things and turn to the next page!

(3) Solve the equation, I have no problem! (9%)

4÷23 X = 25 8(X-2)= 2(X+7)320: 18% = 6.5x

The second part: "Animation" world, exploring and innovating.

You must be familiar with the following figures, so please start with your hands and success belongs to you!

(1) There are 1 cubic decimeter 12 cubic commodities. Please design a rectangular box for it. * * * There are () kinds.

Different packaging methods; When the length, width and height of the packing box are () decimeters,

The most economical wrapping paper. At least () square decimeter of wrapping paper is required (seams are ignored). (5%)

The diameter of the street garden is 5 meters. Now, a circular road with a width of 1 meter is built around it. Please press 1250.

Draw the design drawing in proportion and calculate the actual area of the road surface. (3%+2%)

Count it as O.

abac

(3) The side length of the small square desktop is 1 meter. Expand its four sides to form a round desktop (as shown below).

Find the area of the circular desktop. (3%)

Part III: Go into life and solve problems.

There are many problems in life related to mathematics. Can you solve these problems? I believe you can do it!

1. Only column types are not counted: (8%)

Xiaoming spent eight days reading a book. He reads two more pages of this book every day 19. How many pages are there in this book?

Column type:

③ Two cars, A and B, are driving in opposite directions from two places at the same time. Car A travels 45 kilometers per hour and car B travels 42 kilometers per hour. Two cars meet at the midpoint 12km. How many hours passed after the two cars left at the same time?

(2) If you subscribe to a newspaper on a monthly basis without any discount, you need 10 yuan. If you subscribe once a year, you can get a discount of 10%. How much does it cost to subscribe for one year?

Column type:

(4) a shopping mall to participate in property insurance, the insurance amount is 40 million yuan, the insurance rate is 0.75%. Due to the accident, the value of lost goods reached 6.5 million yuan, and the insurance company compensated 5 million yuan. How many million yuan did the mall actually lose?

Line: line:

2. Graph-column calculation: (5%)

For the sake of students' health and safety, the school provides each student with a water cup, with a 10% discount on each water cup in Sanyuan and Ocean Mall, and "buy eight and get one free" in Baihui Commercial Building. The school wants to buy 180 cups. Please be a "staff officer" and calculate: which is more cost-effective? Please write down your reasons. (5%)

4. A two-story bookshelf, there are more books in the upper layer than in the lower layer 18. If you take out 65,438+0065,438+0 books from the upper level and put them in the lower level, the number of books in the two levels is equal. How many books are there on the upper and lower floors? [solved by equation] (5%)

5. Students from a school have a spring outing. If 45 buses are rented, 15 people have no seats. If you rent the same number of 60 buses, one bus is empty. It is known that 220 yuan rents 45 buses and 300 yuan rents 60 buses.

Q: (1) How many students are there in this school? (3%) (2) What is the most economical way to rent a car? (2%)