1. Xiaoshengchu Olympiad Mathematical Problem Summary: Application Problem
1, the red family ate three apples for the first time, eight apples for the second time, and how many apples did they eat twice? 2. There are 15 branches. Take seven sticks. How many sticks are left?
3. There are 9 people in the van, 4 people in the car, and how many people in two cars?
4. Beibei wants to be a 1 1 windmill. Six windmills have been built. How much more will be made?
5. It's obvious that 13 flowers were made, and 6 flowers were made. How many more flowers do you want to make?
6. Nini's family has 12 cabbages. After eating 9 cabbages, how many cabbages are left?
7. The army has completed five 13 paper boats. How much more will be built?
8. There are 8 big sheep and 6 little sheep on the grass. How many sheep are there in a * * *?
9. There are 14 red flowers and yellow flowers, 7 red flowers and how many yellow flowers?
10. How many red goldfish and platinum fish are there in Mingming's family?
2. Summary of Xiaoshengchu Olympiad Mathematical Questions: Application Questions
1. There are 10 birds in the tree. How many birds are left after seven flies? 2. Xiaoming wrote eight characters on the first day and 10 on the second day. How many big characters did he write in two days?
There are 10 apples on the plate. Xiaohong ate four apples. How many apples are left?
Xiaoyun made seven flowers and brought three more. How many flowers are there now?
5. Xiaojun used 10 pencils twice, six pencils for the first time and several pencils for the second time.
6. The school has 17 balls and has borrowed 10 balls. How many balls are left?
7. Huanhuan made five big red flowers and Beibei made eight big red flowers. How much did they do together?
8. Lele has pears and apples *** 15, eight apples and several pears?
9. Yun Yun drew six flags and five in red. How many did they draw?
10, it is obvious to do 16 flowers. Six flowers are ready. How many more do you have to make?
3. Induction of Xiaoshengchu Olympic Mathematical Problems: Application Problems
1. Students make 36 red flowers, 15 yellow flowers. How much less yellow flowers are than red flowers? Damin's family collected 20 cabbages and 23 lettuce. How much less cabbage is than lettuce?
3. Senior two students plant 30 flowers, how many 50 flowers will there be?
4. Xiaojun and Mingming jump rope. Xiaojun jumped 45 times and Ming Ming jumped 37 times. How many times less than Xiaojun?
There are 46 fruit trees in the orchard. There are more pear trees than apple trees 12. How many pear trees are there?
6. There are 18 rabbits and 7 black rabbits in the school. How many white rabbits are there than black rabbits?
7. There are 16 red goldfish in the fish tank. There are eight red goldfish in Huang Jinyu, and how many in Huang Jinyu?
8. Xiaoli patted the ball, 70 times twice, 30 times for the first time, and how many times for the second time?
9. Eight children drew 20 red flags, as many as yellow ones. How many flags did a * * * draw?
10. There are 47 peach trees and 36 pear trees in the orchard. How many pear trees are fewer than peach trees? Eight more pear trees were planted. How many pear trees are fewer than peach trees now?
4. The induction of Xiaoshengchu Olympic Mathematical Problems: Travel Problems
1. On the circular runway, A and B start from point A and go in opposite directions at the same time. Eight minutes later, they met. Six minutes later, A arrives at point B. 10 minutes later, the two meet again. A How long does it take to make a circle? Answer: 28 minutes
Analysis: Assuming that the total running time is S, Party A and Party B walk AB together for the first time, S+AB for the second time, 8 minutes for the first time, and 6+ 10= 16 minutes for the second time, then the time for them to walk AB together is half of the whole S time, according to the speed and calculation.
Xiaoming and Xiaoying go back and forth to A and B respectively on the expressway. Suppose at the beginning, they walk in opposite directions from two places. If they meet for the first time at a place 3 kilometers away from A and meet for the second time at a place 2 kilometers away from B, what is the distance between A and B?
Answer: 7 kilometers
Analysis: Xiao Ming met for the first time and walked 3 kilometers. When we met for the second time, Xiao Ming walked 3 kilometers, met 9 kilometers, and subtracted 2, it was 7 kilometers. This kind of problem has a formula (2N- 1)=M (where n is the number of encounters and m is the total length of two people * * *).
3. Party A and Party B run around the circular track at a uniform speed, starting at both ends of the circular diameter. If they start at the same time and meet for the first time when A runs 60 meters, and meet for the second time when B is 80 meters short, what is the length of the runway?
Answer: 200 meters
Analysis shows that Party A and Party B ran for one and a half laps when they met for the second time. At this time, Party A ran 60 * 3 =180m, and the total length was reduced by 80m. Then 1.5S=S-80+ 180 gives the total length of S equal to 200m.
5. The induction of Xiaoshengchu Olympic Mathematical Problems: Travel Problems
1, Xiaogang and Xiao Qiang rented a boat, rowed upstream and accidentally dropped the kettle into the river. When they found and adjusted the bow, the kettle was 2 kilometers away from the ship. Assuming that the speed of the ship was 4 kilometers per hour at that time and now it is 2 kilometers per hour, how long will it take them to catch up with the kettle? Answer: 0.5 hours
Analysis: For a typical running boat problem, when the boat turns around to chase the kettle, the speed difference between them is 2+4-2 = 4km/ hour, and the chasing distance is 2km, so the chasing time = distance difference ÷ speed difference = 2 ÷ 4 = 0.5h ..
2. Party A and Party B train on the elliptical track and run in reverse from the same place at the same time. After finishing the first lap, everyone goes back to the starting point and turns back immediately to speed up the second lap. In the first lap, B's speed is 2/3 of that of A, A's speed in the second lap is higher than that in the first lap 1/3, and B's speed in the second lap is higher than that in the first lap 1/5. It is known that the second intersection of A and B is 0/90 meters away from the first intersection/kloc. How long is this oval runway?
Answer: 400 meters
Analysis: As shown in the figure below, point A is the starting point. Because the speed of the first lap B is 2/3 of that of A, the distance from point B to A for the first time is 3/5 of the whole journey. When A finishes a lap and reaches point A, point C is 1/3, at which time A accelerates 1/3, and the speed ratio of A and B becomes 2. The distance between them is 65438+ 0/3 of the whole journey. At this time, B accelerates 1/5, and the speed ratio between Party A and Party B becomes 4: 12/5 = 5: 3. At this time, it becomes an encounter problem with a distance of 1/3. When Party A and Party B meet for the second time, Party B takes 1/3 of the total length. Therefore, the distance BD between two intersections is 3/5- 1/8= 19/40 of the total length, so the total length of the elliptical runway is 190÷ 19/40=400 meters.
The express train and the local train leave from A and B at the same time, in opposite directions, and meet after 5 hours. It is known that it takes 12.5 hours for the local train to travel from B to A, and it will stay in A for 0.5 hours before returning. The express train stops in bilibili 1 hour and returns, so how long will it take for the two cars to meet for the first time and the second time?
Answer: 54/5 hours
Analysis: Because the meeting time between the slow train and the slow train is 5 hours, it takes 12.5-5=7.5 hours for the slow train to reach A, and the journey of the slow train of 7.5 hours is just equal to the journey of the express train of 5 hours. Because the distance is constant and time is proportional to speed, V is fast: V is slow =t is slow: T is fast = 7.5: 5 = 3.2.