1. I can put the correct answer in brackets in the PK competition. (2 points for each small question, ***20 points)
1. "The number of six classes (1) is the number of six classes (2)" means that () is regarded as the unit "1", and () accounts for (). If Class 6 (2) has 42 students, then Class 1 * * has () students.
2.=( )∶( )= 140%=35÷( )=( )。
3. Divide the rice noodles into three parts on average, each part is () meters long, and the second part accounts for the whole length.
There are more than 200 countries in the world, including more than 100 countries with water shortage and more than 40 countries with severe water shortage. Countries that are short of water account for about ()% of the total number of countries in the world, and countries that are seriously short of water account for about ()% of the total number of countries in the world.
5. A hotel 10 has a turnover of 300,000 yuan. If the business tax is paid at 5% of the turnover, the hotel should pay business tax () yuan in 10.
6. The circumference of a semicircle with a diameter of 10 decimeter is () decimeter.
The reciprocal of 7.80% is () and the reciprocal of 1 is ().
8. Add 25g of salt to100g of water, and the salt content of brine is ().
The ratio of 9: 0. 125 is (), and the ratio with the simplest integer is ().
10. Cut a cube into two small cuboids, and the surface area of the cube is the sum of the surface areas of the two cuboids.
Second, I am an impartial judge who can accurately judge right and wrong. (Mark "√" for the right and "×" for the wrong. 5 points)
The latter item is 1 1. 4: 5 increased 10. In order to keep the proportion unchanged, the previous item should be increased by 8. ( )
The maximum number between 12.0.67 and 66.7% is 66.7%. ( )
13. The quotient of a number divided by a fraction must be greater than the original number. ( )
14. For goods with a price of 100 yuan, the price will be increased by 20% first, and then reduced by 20%, which is still the original price. ( )
15. The number A divided by the number B is equal to the reciprocal of the number A multiplied by the number B. ( )
Happy ABC, I chose quickly and accurately. (2 points for each small question, *** 10)
16. In the figure below, the symmetry axis is at least ().
A, rectangle b, square c, isosceles triangle d, circle
17. The radius of the circle is enlarged by 4 times and the area is enlarged by () times.
a、4 B、8 C、 16 D、√
18. First use a 2-meter-long rope, then use the rope to remove the rice, leaving () meters.
a、 1 B、C、 1 D、
19.X, y and z are three nonzero natural numbers, and X × = Y× = Z×, then the descending order of x, y and z should be ().
A.x； y； z； B； z； y； c； y
20. When deducing the formula of circle area, divide a circle into several equal parts and spell it into an approximate rectangle. The length of this rectangle is ().
A, radius b, diameter c, circumference d and half of the circumference.
Fourth, be careful, I will calculate. (28 points)
2 1. Write the number directly. (4 points)
÷= ×3= 6×= +×7=
100÷ 10%= ÷ 1= ÷7= ×9×=
22. Calculate the following questions, and simplify what can be simplified. (8 points)
( 1) (3)( 15- 14×)×
(4)÷[(+ )×] (6)×+×
23. Find the unknown number ⅹ. (6 points)
ⅹ+ⅹ= 15 ⅹ∶=∶
24 column calculation (6 points)
(1) times a number, and the product is, what is this number?
(2) What is the product of 25 and less than 25?
25. A circular ring with a radius of 12 cm and an inner radius of 8 cm. What is the area of this ring in square centimeters? (4 points)
Fifth, comprehensive practice. (10)
26. The overlapping area of two rectangles is equivalent to that of a large rectangle and a small rectangle. What is the area ratio of large rectangle to small rectangle? (3 points)
27. Draw the largest circle with a length of 4 cm on the left side of the square. (4 points)
Requirements: ① indicate the center of the circle.
(2) Point out what radius is.
(3) Calculate the circumference of the circle in centimeters.
Perimeter centimeter
28. Draw all the symmetry axes in the picture below. (3 points)
Sixth, solve the mathematical problems in life. (27 points)
29. Zhang Hua read a story book. In the first week, he read the whole book. In the second week, there were 120 pages left. (every grid 1 minute, 4 points)
(1)+ means:.
(2)- It means:.
(3) 1- means:
(4) 120 \u[ 1-(+)] means:
30. Three households * * * use a master table, and1February * * * pays 384 yuan for electricity. How much should each family pay according to the number of people in each family? Fill in the table below. (3 points)
resident
Zhang (surname)
Li Jia
the Wangs
Number of permanent residents (persons)
three
four
five
Electricity payable (yuan)
During the period of 3 1. Spring Festival travel rush, after the air ticket price from Shenzhen to Wuhan increased by 10%, the air ticket price was 880 yuan. How much is the air ticket price before Spring Festival travel rush? (5 points)
Xiaoling took part in the math contest. The total number of questions in the whole volume 18, Xiaoling only got the total right. How many questions did Xiaoling do wrong? (5 points)
33. Of China's population of 654.38+0.3 billion, urban population accounts for about 40%, and developed countries account for about 70%. How many hundred million will China's urban population increase to reach the level of developed countries? (5 points)
34. In order to build a conservation-oriented society and strengthen citizens' awareness of water conservation, a city has formulated the following water fee standards: when the monthly water consumption of each household does not exceed 10 ton, the water fee per ton is 0.8 yuan; If it exceeds 10 ton, the water fee will be increased by 50% on the basis of each ton of 0.8 yuan. The Wangs used 18 tons of water last month. How much will it cost? (5 points)
7. Choose a question (if all the previous questions are finished and no mistakes are found after repeated inspection, and there is enough time to do this question, the score of this question is not included in the total score, and it is written at the back of the total score with four grades of A, B, C and D).
35. The criteria for estimating the weight of children of different ages are: 2 ~ 10 years old: weight = age × 2+8; 1 1 to 15 years old: weight = age ×3-2.
The relationship between the percentage of actual weight and standard weight and body shape is as follows.
Actual weight and standard
Weight percentage
20% lighter in weight
exceed
10% light
To 20%
10% light
Weight 10%
Weight 10%
To 20%
Weight 20%
exceed
Body type (grade)
lose weight
filmy
normality
fat
fat
Xiaodong: I am 10 years old and weigh 25 kilograms.
Wang Wei: I am 1 1 years old and weigh 27kg.
Please analyze it by mathematical calculation. What should they pay attention to if they want to reach a normal body shape?