1. Mathematical thinking training in summer vacation for the third grade of primary school
1. There are 25 students in the school art group, and the singing group is more than the art group 17. How many people are there in the two groups? My mother is 32 years old, 24 years older than Cong Cong. How old is Cong Cong?
3. A rope is folded in half, and then folded in half. Each section is 5 meters. How long is this rope?
4. A piece of cloth is 60 meters, cut 5 meters at a time, cut 9 times, how many meters are left?
5. The school bought/kloc-0 football with 20 yuan, and 29 yuan bought a basketball. How much is a basketball more expensive than a football?
6. There are 27 apple trees in the orchard, and there are more pear trees than apple trees 17. How many pear trees are there?
7. Xiaoming read a story book. On the first day, he read six pages less than the next, and the next day he read 30 pages. How many books did he read on the first day?
8. My brother is 9 years old today, and my brother 15 years old. /kloc-how old is my brother after 0/0 years?
9. It takes 5 minutes to saw a piece of wood into 5 sections. How many minutes does it take to saw it once?
10, Grandma can't buy back 20 pieces of candy, and there are 2 pieces left in the quantity of 3 pieces, and 2 pieces left in the quantity of 5 pieces and 5 pieces. How many sweets did grandma buy?
1 1. There are 7 boxes of pens in the store, each containing 8 pens, and 28 pens have been sold. How many pens are left?
12. Is it enough for 4 people in each room and 26 people in 7 rooms?
13, Xiao Fang borrowed 70 pages of books a week. She plans to read 9 pages every day. Can she finish it on time? If not, how many pages are missing?
14, Xiaoming is 7 years old, his mother is 2 1 year older than Xiaoming, and his father is 5 times older than Xiaoming. How old is his mother? Where's Dad?
/kloc-class 0/5 and class 2 (3) have 28 girls,/kloc-class 0/2 has fewer boys than girls. How many boys are there? How many boys and girls are there?
2. Mathematical thinking training in summer vacation for the third grade of primary school
A, fill in the blanks 1, 4 kg = () grams.
2,20 decimeters = () meters
3, 45 cm = () mm
4, 10 m = () cm
5800 mm = () cm
6, 70 decimeter = () cm
7300 minutes = () hours
8 10 km = () m
9, 47 cm -27 cm = () cm = () decimeter
10, fill in ○ or =.
2 tons ○2200 kg
1 1, 1 ton-40kg = () kg.
12. Fill in ○ or =.
3: 00: 300
13. Fill in ○ or =.
490g ○ 1 kg
14, 1 m +3 decimeter = () decimeter
15, in ○
4 meters ○400 cm
16,41mm+159mm = () mm = () decimeter.
Second, the oral calculation questions
15×4×3= 480÷8÷6= 80÷4+6=
8 10÷(4+5)= (43- 13)×6= 20÷6×4=
100- 12×8= 60+ 18×5= (24+ 16)÷8=
Third, the text narrative questions
1 and 250 tons. How many times is 5 tons?
How many decimetres is twice 2.36 decimetres?
3. Mathematical thinking training in summer vacation for the third grade of primary school
1. Father and son lost 60 this year. It is also known that four years ago, the father's age was exactly three times that of his son. How old is his son this year? Analysis and answer: Four years ago, the sum of the ages of father and son was 60-4×2=52 years old. Four years ago, my son's age was 52÷( 1+3)= 13, so this year my son's age is 13+9= 17.
2. The express train and the local train leave from Party A and Party B respectively. If the local train leaves two hours before the start, the local train will exceed the midpoint by 24 kilometers when they meet. If they are happy, they will leave for 2 hours and meet 72 kilometers from the midpoint. If they leave at the same time, they can meet in four hours. How many kilometers per hour is the express train more than the local train?
Analysis and solution: Let half of the whole journey be X, the distance traveled by the express train is x+72+x-24=2x-48, the distance traveled by the local train is x+24+x-72=2x-48, and the distance traveled by the express train is 2x+48-(2x-48) = 96km.
There are three piles of chess pieces, each pile has the same number of chess pieces, and they are only black and white. The number of sunspots in the first pile is as much as the number of Bai Zi in the second pile, and the number of sunspots in the third pile accounts for all the sunspots. If these three piles of chess pieces are put together, what percentage of the total number of chess pieces are albino stars?
Analysis and solution: The third pile of sunspots accounts for all the sunspots, then the sunspots in the first pile and the second pile account for all the sunspots, and because the number of sunspots in the first pile is the same as the Bai Zi number in the second pile, the number of sunspots in the first pile and the second pile is exactly equal to the number of chess pieces in the first pile. If the number of pieces in each pile is regarded as 3, then the total number of pieces in three piles is 9 and the number of spots is 5, then the number of albinos is 9-5=4, so the number of albinos is 9.
At 8 o'clock in the morning, two cars, A and B, drove from the chemical fertilizer plant to the county. The speed of both cars is 48 kilometers per hour. At 8: 32, the distance from the A train to the fertilizer plant is five times that of the B train. By 8: 44, the distance between a car and the fertilizer plant is exactly twice that of b car, so the first car leaves from the fertilizer plant at 8: 00.
Analysis and solution: 12÷3×(3+5)=32 minutes, 8: 44-32 minutes = 8: 12 minutes, so the first car left from the fertilizer plant at 8: 00.
5. What is the smallest natural number with 60 different divisors?
Analytical solution: 60 = 2× 2× 3× 5 = (1+1)× (1+2 )× (2+1)× (4+1), and the minimum natural number is 29.
4. Mathematical thinking training in summer vacation for the third grade of primary school
1, 40 pears are divided into three classes, 20 pears are divided into one class, and the rest are divided equally into two classes and three classes. Two or seven years ago, my mother was six times as old as my son. My son is 12 years old and my mother is () years old.
The students have a radio practice contest, and the whole class is arranged in six equal rows. Xiaohong is in the second row, counting from the beginning. She is in the fifth position, and she is in the third position from the bottom. There are () people in this class.
There is a string of colored beads arranged in the order of "2 red, 3 green and 4 yellow". The 600th color is ().
5. Wrap a rope around the tree for more than 30 cm. If it is wrapped around the tree for four times, it is 40 cm, the circumference of the tree is () cm, and the rope is () cm long.
6. A snail climbed to the bottom of the well at a depth of12m, climbed 3m every hour, and then slipped 2m. It takes a snail () hours to climb out of the wellhead.
7. Saw a wooden stick with a length of 10 meter, and it takes 2 minutes to saw each section. It will take () minutes if this stick is sawed into five equal parts.
8. Three cats ate three mice in three days. At this rate, nine cats can eat () mice in nine days.
9. There is a glass of juice. Xiao Ming drinks half first, then fills it with water, then drinks half, then fills it with water, and finally drinks it all. Does Xiaoming drink more juice or water?
10, there are 10 different locks, and 10 locks have 10 keys mixed together. It takes at most () times to match all 10 locks and keys.
5. Mathematical thinking training in summer vacation for the third grade of primary school.
1. Teacher Zhang has two problems. 13 people answered the first question correctly, 22 people answered the second question correctly, and 8 people answered both questions correctly. How many people are there in this class? Answer: Of the 13 people who got the first question right, 8 also got the second question right, so 8 of the 22 people who did the second question counted again, so add up the number of people who did the first question and the number of people who did the second question, and then subtract these 8 people who repeated the number. Formula: 13+22-8=27 (people), so there are 27 people in this class.
Forty people carry 65,438+000 sandbags, three big ones and one small one. Q: How many people, big and small?
Answer: 30 great people, 10 little people.
Assuming that 40 people are big, then * * * can carry 120 bags, which is more than the actual situation 120- 100=20 (bags). Now, if you change a small man into a big man, the total number of sandbags will be reduced by 3- 1=2 (bags). Because 202= 10 (people), there are 10 small men, and 40- 10=30 (people).
3. There are 50 students going boating in the park, each big ship can take 6 people, and the rent is 10 yuan; Each boat can take four people and rent 8 yuan. So among many different chartering schemes, which one is the most economical?
Answer: Everyone on the ship: 106=5/3 yuan.
Per person: 84=2 yuan.
Big boats are cheap, so rent as many as possible.
506=8+2
Rent eight big boats, and there are two people left.
6+2=8=24
Two small boats are better than two big boats.
So we rented 1 big boat less, and the remaining 8 people rented 2 small boats.
The most economical plan is: lease 7 large ships and eliminate 2.
Rent: 7 10+28=86 yuan.
4. Calculation:18+19+20+21+22+23.
Answer: The original formula =( 18+23)62= 123.
After the math contest, Xiaoming and Obana Xiao Qiang each won a medal. One of them won a gold medal, a silver medal and a bronze medal. The teacher guessed: Xiaoming won the gold medal, Xiaohua won't win the gold medal, and Xiao Qiang won't win the bronze medal. As a result, the teacher only guessed one, so who won the gold medal, the silver medal and the bronze medal?
Answer: Xiaohua won the gold medal, Xiao Qiang won the silver medal and Xiaoming won the bronze medal.
Solution process: (1) If Xiaoming wins the gold medal, Xiaohua will definitely not win the gold medal, which is inconsistent with the teacher's only correct guess.
(2) If Xiaohua won the gold medal, then the sentences that Xiaoming won the gold medal and Xiaohua didn't win the gold medal are both wrong, so it should be correct that Xiao Qiang didn't win the bronze medal, then Xiao Qiang won the silver medal and Xiaoming won the bronze medal.