1, ( 1/( 1× 2)+2/( 1× 2× 3)+3/( 1× 2× 3× 4)+...+9/(65438+)
2、 ( 1.6- 1. 125 + 8(3/4))÷37( 1/6) + 52.3×(3/4 1)
3、 19+ 199+ 1999+……+ 19999…99
└ 1999 9┘
4、 77× 13+255×999+5 10
Fill in the blanks. 30 points
1, the decimal point of a decimal point moves to the right and left respectively, and the difference between the two numbers is 2.2, then the decimal point is expressed as a fraction.
2. Price of a leather coat 1.650 yuan. If you sell it at a 20% discount, you can still make a profit 10% (relative to the purchase price). If it is sold at the price of 1650 yuan, it can make a profit in RMB.
3. The speed of a ship sailing downstream is 30 km/h, and it is known that the voyage of sailing downstream for 3 hours is equal to the voyage of sailing upstream for 5 hours, so the voyage of this ship drifting downstream 1 hour is () km.
There are 1.800 students in Tsinghua High School. If each student has 8 classes and each teacher has 4 classes every day, then each class is 45 students, 1 teacher. So please introduce that Tsinghua High School has a teacher's name.
5. Add 3 to a number, divide it by 3, then subtract 5 and multiply it by 4, and the result is 56. This number is _ _ _ _ _.
6. Some students in Class One of Grade Six are 13 years old, some are 12 years old, and the rest are 1 1 years old. The average age of the students in this class is _ _ _ _ _.
7. Put 25g of sugar into an empty cup, pour100g of boiling water, fully stir, and drink half of the sugar water. Add 36 grams of boiling water. If the sugar water in the cup is as sweet as before, you need to add _ _ _ _ _ grams of sugar.
8. Mother Panda's baby-Little Panda is 2 years old this year. A few years later, when the little panda and the mother panda were the same age, the mother panda was 18 years old. Mother panda is _ _ _ _ _ years old this year.
9. Fill in the following "□" with appropriate operation symbols to hold the equation: (1□ 9 □ 2) × (1□ 9 □ 2) × (19 □ 9 □ 2) =1992.
10, the circumference of the circular runway is 400 meters. Two athletes, A and B, set off clockwise from the starting point at the same time. A's speed is 400 meters/minute, and B's speed is 375 meters/minute. () Minutes later, Party A and Party B meet again.
Third, column calculation. 50 points
1, there are 9 small rectangles, their length and width are equal, and the area of the big rectangle composed of these 9 small rectangles is 45 square centimeters. Find the circumference of this big rectangle.
2. A train passes through a 900-meter-long railway bridge, and it takes 1 minute and 25 seconds to get on the bridge in front and get off the bridge in the back. Then the train passes through a tunnel with a length of 1800 meters, and it takes 2 minutes and 40 seconds to get the speed of the train and the length of the car body.
3. Gardeners should plant trees equidistantly at the edge of a circular flower bed with a circumference of 300 meters. They first dug a hole every 3 meters along the edge of the flower bed. When they finished digging 30 holes, they were suddenly told that they would plant a tree every 5 meters instead. In this way, how many holes will they have to dig to complete the task?
4. Two construction teams, Party A and Party B, are building a 4200m-long highway, and Team B is building 100m more than Team A every day. Now it will be repaired by engineering team A for 3 days. The rest of the road sections were jointly repaired by Team A and Team B, and it took only 6 days to complete. Q: How many meters do the A and B engineering teams build roads every day?
5. A person rides a bicycle from the county seat to the township to set up a factory. He started from the county seat by bike and completed half the journey in 30 minutes. At this time, he sped up, driving 50 meters more every minute than before. After riding for another 20 minutes, he knew from the mileage card on the roadside that he had to ride another 2 kilometers to set up a factory in the township, and asked for the total distance from the county to the township.