1, the radius of a circle is 3cm, the circumference of a half circle is () cm, and the area of this circle is () cm2.
2. More than 1 2m1m/h () m.. /kloc-more than 0/2 meters is () meters. 66
3. Cylinders and cones have the same base height, and their volume difference is 24 cubic decimeters. Then the volume of the cone is () cubic decimeter, and the volume of the cylinder is () cubic decimeter.
4. The inner diameter of the tap water pipe is 1 cm, and the flow rate of water in the pipe is 8 cm per second. A classmate went to wash his hands and forgot to turn off the tap when he left. Another classmate 10 minutes only to find it off, wasting () water.
5. A positive integer with a mantissa of about 990,000 after omitting ten thousand digits. Ask whether the maximum quantity is () and the minimum quantity is ().
6. Fold a 24 cm rope in half once, and then fold it in half again. If you cut from the middle at this time, the longer () segment accounts for () cm of the whole length. ()
27, numerator plus 8, to make the size of the fraction unchanged, the denominator should be added (). five
8. The greatest common factor of two natural numbers is 12 and the smallest common multiple is 144. These two numbers are () or ().
9. The sum of all sides of a cuboid is 192 cm, and the ratio of length to width is 7:5:4. The volume of this cuboid is () cubic centimeters.
10, a divided by b, the quotient is 1 19, and the remainder is 8. If the number A is expanded to 10 times, the quotient of the number B multiplied by 10 is () and the remainder is ().
Second, true or false (65438+ 0 points for each small question, ***5 points)
1. Divide a big triangle into two small triangles, and the sum of the internal angles of each small triangle is 90 degrees. ()
There was a difference of one ton between the two piles of goods. If the two piles of goods are shipped 20% each, the difference between the remaining goods is still one ton. ()
3. All prime numbers are odd numbers. ()
If all sides of a cuboid are 6 cm long, its surface area and volume are equal. ()
5. The quotient of a number divided by a true fraction must be greater than the original number. ()
Three, multiple-choice questions (65438+ 0 points per question ***5 points)
1. Add 5g of sugar and 20g of water to the sugar water with a sugar content of 20%. At this time, there is more sugar water than before ().
A, sweet B, not too sweet C, just as sweet.
2, estimate the calculation results of the following four formulas, the biggest is ()
1? 1? a、20 1 1 1？ 20 1 1 1B 、? 20 1 120 1 1
1? 1? c、20 1 1 1？ D20 1 1？ 1? 20 1 120 1 1?
3. From city A to city B, it takes 4 hours for car A and 5 hours for car B. Then, car A is faster than car B ().
A, fast 25%B
25%C, 20%D, 20% slow.
Throw a coin three times, and two heads are up, 1 tails are up, so the possibility of throwing a coin for the fourth time is ()
a、 12 1 1B、C、D、4332
A rope is cut into two sections, the first section is meters long, and the second section occupies the whole length. Compared with these two pieces of rope, () 33
A, the first paragraph is B, the second paragraph is C, and the two paragraphs are as long as D, so they can't be compared.
Four, the calculation problem (***30 points)
1, solve the equation (3 points for each small question, ***6 points)
( 1)0.8:X？
2. Calculate the following questions as simply as possible (4 points for each small question, 24 points for * * *).
5? 527? 575? 1( 1)? (2)68 12? 24? 6? 147 184? 1? 1:0.2(2)? x？ 0.33? 19.53? 4? five
(3)20.07× 1994- 19.93×2007(4)2.5? 0.875? 0.25? 1.25
888 15 12(5)999? 99? 9? (6)2.5? 9993 1267
Five, solve the problem (each small problem 5 points ***40 points)
1, three teams planted 2 10 trees, and one team planted them altogether.
At 2:5, how many trees were planted by the three teams?
2. Put the water into a cylindrical measuring cup with a bottom radius of 4 cm and a height of 10 cm. Put a small iron ball into the water, and it overflows when it is full15.7 g. What is the volume of the small iron ball? (1 cubic centimeter of water weight 1 gram)
The garden team is going to plant a batch of saplings. Two10 saplings were planted on the first day, and the remaining 20% were planted on the second day. Two days later, two seedlings were not completed. How many saplings are there? 52, the ratio of the second team to the third team is 5.
4. A ship sailed from Port A to Port B at a speed of 40 kilometers per hour, and after completing 20% of the whole journey, it traveled 1 hour. At this time, the ratio of the distance traveled to the distance not traveled is 65,438+0: 3. How many kilometers is it between Port A and Port B?
5. Dad plans to lay the foundation for Liang Xiao's research. It takes 128 to use a square brick with a side length of 3 meters. If you use a square brick with a side length of 2 meters, how many pieces do you need? How many square meters is Liang Xiao's study?
6. Mother squirrel can pick 20 pinecones every day in sunny days, and only 12 in rainy days. She picked 1 12 pinecones for several days, with an average of 14 pinecones per day. How many days has it rained these days?
7. Test your comprehensive ability.
(1) There are some rectangular pieces of paper, 5 cm long and 4 cm wide. What is the area of a small square made of these pieces of paper (no overlap, no gap)? How many rectangular pieces of paper do you need?
(2) As shown in the figure, what is the area of the shaded part in the figure?
Six, additional questions (20 points)
There is salt and water in the laboratory.
(1) Please prepare 500g of salt water with a salt content of 5%. How many grams of salt and water do you need to prepare?
(2) If it is required to change 500g of brine from (1) to 15% brine, how many grams of salt should be added?
(3) If you are required to prepare 5000 grams of brine with salt content of 12%, how many grams should you take from two kinds of brine with salt content of 5% and 15% to prepare?