1. Logical problems of brain teasers in Olympic mathematics in primary schools
1, mother duck leads her children to learn to swim in the pond. She is afraid of losing her child. She always counts, from back to front, from front to back. She is 7 years old. You said mother duck has () children. 2, a book, Xiaohong read 1 page on the first day, then read 1 page more than the day before, and read () page on the fourth day.
3, a rope with 2 cut 1 time, with () cut twice.
There are three pairs of black socks and three pairs of white socks in the pocket, which are put together at sixes and sevens. If you want to touch it from your pocket, at least () pairs of socks should be found to ensure that they are matched into a pair of socks with the same color.
There are some birds on this big tree and this small tree. Now three birds fly away from the big tree, 1 birds fly away from the small tree. There are as many birds in these two trees. Think about it. Which tree has fewer birds? How much is missing?
2. Primary school mathematics Olympic brain teaser logic questions
1. Mr. Wu bought some snacks to visit a friend. Who knows, these snacks were stolen by his son, but he doesn't know which one. To this end, Mr. Wu was very angry and questioned his four sons who stole snacks. The boss said, "I was eaten by the second child." The second said, "The fourth stole it." The third said, "I didn't steal it anyway." Old four said, "Old two is lying." Only one of the four sons told the truth, and the other three were lying. So, who stole these snacks? 2. There is a big truck full of goods passing through bridge opening, but there are too many items on the truck, and the top of the truck is higher than that of bridge opening 1cm, so it can't pass. Is there any way to get this truck through bridge opening smoothly?
3. A king got acute appendicitis. The king invited three highly skilled doctors to operate on themselves in turn on the same day. Because there was a plague at that time, anyone could carry the virus, so there was no contact between the king and the three doctors and between the three doctors to prevent infection. But there are only two pairs of sterilized surgical gloves. What's the safest thing to do?
3. Elementary school mathematics Olympic brain teaser logic questions
1. The child wants to climb a tree 6 meters high, but every time he climbs 4 meters, he falls 2 meters. The little monkey can only climb to the top of the tree for the first time. 2. When you get home at night, pull the switch and the light will come on. Pull the switch again and the light won't work. As soon as the naughty dog got home, he pulled the 10 switch. Do you think the light is on or not? Pull it 47 times, bright (), not bright ().
3, a rope is 8 meters long, and then folded in half, each fold is () meters long?
4. Draw "√" after the answer you think is correct.
Xiaohong can buy three cakes or four loaves of bread with the same money. Is cake more expensive () or bread more expensive ()?
(2) White Cat caught as many fish as Xiaohua Mall, and after giving some to Grandma, White Cat had two fish left, and Xiaohua Mall had 1 fish left. Who gave grandma more fish?
Three boys and three girls play ball together. If every male student wants to compete with every female student once, then a * * * needs to compete () times.
6. Saw a piece of wood into 5 sections and saw it () times.
7. In the second grade, 50 athletes participated in the school long-distance running competition, ranking 50th. There are () "1" in these figures.
8. 45 balls in the gym, 9 for the first time and 10 for the second time. There are fewer balls in the gym than before.
Lingling read a 70-page book. On the first day, she read 18, the next day 10, and the third day ().
10, my sister and brother each have 12 pencils. After writing with the same number of pencils, my brother left 1 and my sister left ().
4. Primary school mathematics Olympic brain teaser logic questions
1, modesty (guess number) 7 2, where (guess number) 2.
3. One thousand (guess a number) ten.
Although the number is small, it is over one million (guess a number).
5.AB actors (a mathematical noun) complement each other.
6. There is no water in Mount Tai (guess a number) 3
7. The expansion diagram of Jing Ke stabbing Qin Wang (creating a mathematical term)
8. Recruit actors (type a mathematical noun) to fill the corner.
9. You expect me, and I expect you to be equal.
10, peak (a mathematical noun) vertex
1 1, Double Ninth Festival every year, now Double Ninth Festival (use a mathematical noun).
12, 3, 4, 5, 6, 7, 8, 9 (to borrow an idiom) is short of clothes and food (one is short of ten).
13, almost the same (using a mathematical noun) is approximately equal to
14, and then don't come back (take a geometric ray)
15, one minus one is not zero (one word) three.
5. Elementary school mathematics Olympic brain teaser logic questions
1, iron mouth, love to eat paper, wholeheartedly do good for the people, press its nose and it will bite people and bite off an iron tooth (smashing office supplies)-answer: stapler 2, a bird killed one, why didn't the other nine fly? Answer: Because it is a group of ostriches.
3. How much are three hearts worth? Answer: 200 million
After graduation (name a festival)-Answer: National Day.
5, the stone should be prominent, don't guess the right word (type a word)-answer: stone.
6. What animal do students like to marry best? -Answer: Rats
Xiao Ming ran for ten minutes in the wilderness of heavy rain. Why is his clothes wet and his hair not? Answer: Xiao Ming is bald.
8, young and ignorant (make a place name in Hubei)-Answer: Dawu
9. The treasure house of thousands of layers is opened, and it is dark and criss-crossed. It records the events of past dynasties, without which knowledge cannot be spread. Answer: books.
10, a sunflower is really strange. It's open in the sea, and its color is good or not. Small fish and shrimp is its dish (killing an animal)-answer: anemone.