Math problems in the second volume of the fourth grade

1. Use a rope with a length of 150 cm to form an equilateral triangle. How long is each side of this equilateral triangle?

2. The two adjacent sides of an isosceles right triangle are 8m and 5m respectively. What's its circumference?

What is the circumference of an isosceles triangle surrounded by strips of 3.20 decimeters and 50 decimeters?

The top angle of isosceles triangle is half of the bottom angle. What are the top and bottom angles of this triangle?

5. equilateral triangles and squares have equal perimeters. The side length of a square is 12 cm. What is the side length of an equilateral triangle?

6. A regular triangular flower bed was built in the happy community, and 15 pots of chrysanthemums were placed on both sides of the flower bed (one pot at each vertex). How many pots are put in a * * *?

7. The two straight lines A and B in the picture below are parallel to each other. Are the heights on the bottom sides of the following four triangles equal in length? Why?

8. The capacity of a bottle of juice is 650ml. How many milliliters is there in a box of juice?

9. Sun Jun poured 1 liter of milk into two identical cups. If the milk in each cup is 300 ml, how many ml of milk is left in the bottle?

10. There are about 5 drops in a millilitre of water, and there are 50 people in the class. How many milliliters 1 drop of water does each person save every day?

11.6 June 14 is World Blood Donation Day. At noon this day, 320 people in a city participated in voluntary blood donation. Voluntary blood donors generally donate 200 ml each time. How many liters is the blood donation?

12. A cold medicine, a bottle of liquid medicine 100 ml, with a dose reminder on it (as shown in the following table). Xiaojun 10 years old. He drank at least one bottle of medicine, and how many times at most?

13.93 gasoline price per liter is around 7 yuan. If a taxi uses 20 liters of gasoline a day, how much will it cost per month (calculated by 30 days)?

14. The school organizes students to participate in tree planting activities. There are 72 plants planted in the low grade, the number of plants planted in the middle grade is three times that of the low grade, and the number of plants planted in the high grade is 20 more than the sum of the plants planted in the middle and lower grades. How many trees are planted in the senior grades?

15. The fruit shop sent 625 kilograms of bananas and 480 kilograms of oranges. Bananas are 25 kg in a basket and oranges are 20 kg in a basket. How many baskets are bananas more than oranges?

16. There are 30 pens in the stationery store, and there are 12 ballpoint pens that are three times more than pens. How many ballpoint pens are there than pens?

17. The vehicle factory wants to produce 1440 tricycles. Originally planned to produce 60 tricycles a day, 80 tricycles were actually produced every day. Can you finish it a few days in advance?

18. Uncle Wang bought a laptop by installment. Make a down payment of 3,000 yuan, and then pay back 245 yuan every month, and pay back * * * 12 months. If you pay at one time, you only need to pay 5200 yuan. How much more does it cost to pay by installment than by lump sum?

19. Xiaojun reads story books, reading 25 pages every day. After reading for five days, he read five more pages, which is exactly half of the book. How many pages are there in this book?

20. There are a bunch of pears and a bunch of peaches with the same weight. Pears sell 17kg, peaches sell 4 1kg. The remaining pears weigh three times as much as the remaining peaches. How many kilograms of pears are there?

2 1. Wang Xiaoliang walks from home to the library to borrow books. Walk every minute/kloc-0.05 meters, and walk to the library in about 28 minutes. How far is his home from the library? (estimated)

22. The speed of sound is 340 meters per second. There is a waist drum team performing in the square. /kloc-What is the sound propagation distance after 0/8 seconds?

There are three classes in Grade Five. There are 45 students in Class One, 48 students in Class Two and 46 students in Class Three. This semester, the school organized social practice activities, and everyone paid 80 yuan's activity fee. How much does this activity cost?

24. Wang planted 125 trees on the hillside last year, and the number of trees planned to be planted this year is 40 times less than last year. How many trees are planned to be planted this year?

25. The experimental primary school bought 78 sets of school uniforms of the same size, including 95 yuan for each coat and 80 yuan for each pair of trousers. How much did you spend on these school uniforms?

26. Zhang Ping plans to travel to Beijing in August. The estimated expenditure is as follows:

Round-trip train ticket (RMB), food (RMB/day), accommodation (RMB/day), tickets and shopping (RMB/day)

550 40 120 200

If you stay on the train for 2 days, you have to call 15 days.

(1) Please calculate how much the tickets and shopping will cost.

(2) How much does the meal cost?

Reference answer:

1. 150÷3=50 (cm)

The length of each side of this equilateral triangle is 50 cm.

2.8+5+5 = 18 (m)

A: Its circumference is18m.

3.20+50+50 = 120 (decimeter)

Answer: The circumference of an isosceles triangle is 120 decimeter.

4.180 ÷ (1+2+2) = 36 36× 2 = 72 (times)

A: The top angle of this triangle is 36 and the bottom angle is 72.

5. 12×4÷3= 16 (cm)

Answer: The length of an equilateral triangle is 16 cm.

6. 15× 3-3 = 42 (basin)

A * * * put 42 pots.

7.a: These heights are equal in length. Because the height on the base of these four triangles is the distance between this group of parallel lines, and the distance between parallel lines is equal everywhere.

8.650× 12=7800 (ml)

A: A box of this juice weighs 7800 ml.

9. 1L = 1000ml

1000-300× 2 = 400 ml

There is still 400 ml of milk in the bottle.

10.50÷5= 10 (ml)

A: Yes 10 ml.

1 1.320×200=64000 (ml)

64000ml = 64L

A: The blood donation is 64 liters.

12. (1)100 ÷12 ≈ 8 (times)

It will take him at least eight times to finish a bottle of medicine.