1. Saw a 2-meter-long wood into four legs of the same length to make a stool. How high is this stool? Page 6, question 6.
2 meters = 20 decimeters
20÷4 = 5 (decimeter)
The height of this stool is about 5 cm.
2. Mom took Xiaoming to see her grandmother by long-distance bus, the whole journey is 308 kilometers. They leave at 8: 00 in the morning, and the bus travels at an average speed of 80 kilometers per hour. Can you arrive at noon 12? (Question 6 on page 10 of this book)
12 hours -8 hours =4 hours
80× 4 = 320km
308 km < 320 km
We can arrive at noon 12.
Is a 3.2-ton truck loaded with three 600kg machines overloaded? (Question 2 on page 12 of this book)
2 tons = 2000 kg
600×3 = 1800 (kg)
A: No overweight.
There are five machines weighing 600kg, 400kg, 800kg,1000kg and 700kg respectively. How can these machines be loaded and transported at one time? (Question 3 on page 13 of this book)
2 tons =200 kg
A set:
600+400+800 = 1800 (kg)
Another set:
1000+700 = 1700 (kg)
A: One set contains 1800kg.
The other one can be delivered at one time 1700kg.
How much does it cost to buy a globe and a schoolbag with 48 yuan for 5.85 yuan (question 2 on page 17 of the book)?
85+48 = 133 (yuan)
Answer: You need 133 yuan to buy a globe and a schoolbag.
People's education publishing house
6. There are 59 cocks, 77 hens and 85 chickens.
(1) How many chickens and hens are there? (Question 3 on page 17 of this book)
59+77 = 136 (only)
Answer: rooster hen 136.
(2) What other math questions can you ask?
Question: How many cocks, hens and chickens are there?
59+77+85 = 22 1 (only)
Answer: There are 22 1 rooster, hen and chicken.
② Question: How many cocks are fewer than chickens?
85-59 = 26 (only)
Answer: There are 26 fewer cocks than chickens.
③ Question: How many roosters and hens are there than chickens?
59+77-85
= 136-85
= 5 1 (only)
Answer: Rooster hen * * * is 5 1 more than chicken.
7. The Beijing-Guangzhou Center Building is 209 meters high. It is about196m shorter than CCTV Tower. Do you know how high the CCTV tower is? (Question 4 on page 19 of this book)
209+ 196 = 405 (m)
A: The CCTV Tower is 405 meters long.
8. Kunming to Lijiang 5 17 km. We have walked 348 kilometers. How far is it to Lijiang? (Page 23 of this book)
5 17-348 = 169 (km)
A: There is still 169 km to Lijiang.
9. The grocery store delivered 4 10 kg of eggs in the morning and sold 152 kg in the afternoon.
How many kilograms are left? (Question 2 on page 125 of this book)
410-152-174 = 258-174 = 84 (kg)
Step by step (Method 2):
Sold: 152+ 174 = 326 (kg)
Remaining: 4 10-326 = 84 (kg)
A: There are 84 kilograms left.
10. There were 852 tourists in the Science Park in the morning, 265 people left at noon and 403 tourists came in the afternoon. How many tourists are there in the park at this time? How many tourists come to the park all day? (Question 3 on page 25 of this book)
(1) 852-265 = 587 (person)
587+403 = 990 (person)
(2) 852+403 = 1255 (person)
A: At this time, there are 990 tourists in the park. There are 1255 visitors in the park all day.
1 1, Xiaoming's home, Xiaohong's home and school are on the same road. Xiaohong's home is 3 12 meters away from school. Xiaoming's home is only 155 meters away from school. How far is Xiaoming's home from Xiaohong's? What may be the location of their two houses and schools? (Question 6 on page 26 of this book)
Two situations:
The first one is on the same side of the school:
312-155 =157 (m)
The second situation; On both sides of the school:
3 12+ 155 = 467 (m)
A: There are two situations from Xiaoming's house to Xiaohong's house.
On the same side of the school, 157m.
Both sides of the school are 467 meters.
12, a set of sportswear 135 yuan, a pair of sports shoes. How much should 48 yuan's mother return to 200 yuan, the shop assistant? (Pages 27 and 28 of this book)
Spending amount: 135+48 = 183 (yuan)
Found: 200- 183 = 17 (yuan)
Or: 200- 135-48 = 17 (yuan)
Answer: 17 yuan should return it.
13. There were 205 people on the passenger ship, 79 people disembarked before sailing, and 128 people boarded the ship. How many people are there on the passenger ship? (Question 6 on page 30 of this book)
205-79 = 126 (person)
126+ 128 = 254 (person)
A: There were 254 people on the passenger ship when we set sail again.
14. Chickens with 900 eggs. In the morning, 337 chicks hatched. More chicks hatched in the afternoon 1 18 than in the morning.
(Question 2 on page 33 of this book)
(1) How many chicks are hatched in the afternoon?
337+ 1 18 = 455 (only)
(2) How many chicks hatched on this day?
337+455 = 792 (only)
(3) How many eggs are left?
900-792 = 108 (only)
15. Is the rectangular flower bed 5 meters long or 3 meters wide? What is the circumference of this flower bed?
(5+3) × 2 formula: (length+width) ×2= rectangle perimeter.
=8×2
= 16 (m)
A: The perimeter of this flower bed is16m.
16. The side length of a handkerchief is 2 decimeters. Can you wrap it with a 90 cm tape?
2 decimeters =20 centimeters
20×4 = 80 cm2 circumference = side length× 4
80 cm < 90 cm
A: You can use a 90-cm-long ribbon to make a circle.
Or 2×4 = 8 (decimeter) 90 cm =9 decimeter.
8 decimeters < 9 decimeters
A: You can turn around.
17. What is the circumference of a rectangle consisting of two squares with a side length of 1cm?
Length: 2 cm width: 1 cm
(2+ 1)×2
=3×2
=6 cm
The circumference of this rectangle is 6 cm.
18, a rectangular vegetable field, 6 meters long and 3 meters wide. How long is the fence around it? If the fence against the wall is at least how many meters?
( 1)(6+3)×2(2) 18-6 = 12(m)
=9×2 Rectangular circumference
= 18 (m)
Answer: The fence length is18m; If you lean against the wall,
The fence should be at least12m.
19, with 29 blades, each fan is equipped with 3 blades. How many fans can these blades hold?
29÷ 3 = 9 (Taiwan Province) ... 2 (Movie)
Answer; These blades are enough for 9 electric fans.
20. The side length of a regular octagon is 3 cm. After a circle with a ribbon, there is an extra 2 cm. How long is this ribbon?
3×4 = 12 (cm) side length× 4 = square perimeter
12+2 = 14 (cm)
This ribbon is * * * 14m long.
2 1, skipping 32 people, a group of 6 people can be divided into several groups, more people.
32÷6 = 5 (group) ... 2 (person)
A: It can be divided into five groups, and there are two more people.
How many bottles of mineral water can 3 yuan buy for 22.20 yuan, and how much is left?
20÷3 = 6 (bottle) ... 2 (yuan)
A: Six bottles at most, and 2 yuan is left.
23. A rope is 19 meters long. Cut 8 meters to make a long skipping rope. Make a short skipping rope every 2 meters. How many short skipping ropes can you make? How many meters are left
1 9-8 =11(m)11÷ 2 = 5 (root) ...1(m)
Answer: You can make five short skipping ropes and 1 meter.
24. In April, there are 30 days of books, question 3 on page 56.
(1) How many weeks and days are there in April?
30÷7 = 4 (pieces) ... 2 days
(2) If April has five Saturdays and Sundays, when is April 1?
A: Saturday.
How many children's books can 23 yuan and 25.4 yuan buy at most? How much is left? What about 25 yuan?
23÷4 = 5 (Ben) ... 3 (Yuan)
25÷4 = 6 (Ben) ... 1 (Yuan)
A: 23 yuan can buy up to 5 copies, and 3 yuan is left; 25 yuan can buy six copies at most, leaving 1 yuan.
26. There are nine empty tables in the Forest Restaurant. Each empty table can make four small animals. At noon, 35 animals came. Do all the animals have seats?
Method 1: 4× 9 = 36 (only)
36>35
A: We all have seats.
Method 2: 35 ÷ 4 = 8 (sheets) ... 3 (only)
A: We all have seats.
27. There are 20 small animals living in the forest castle, 6 in each room. How many rooms can a * * * have? How many small animals are left?
20÷6 = 3 (between) ... 2 (only)
A: * * * can live in three rooms, and there are two small animals left.
28. See the table below for the number of flowers in the flower shop.
Chrysanthemum and tulip
22 branch 16 branch 10 branch
If you tie 7 chrysanthemums, 3 Chinese rose flowers and 2 tulips into a bunch of such flowers, how many such bouquets can you tie at most?
22÷7 = 3 (bundled) ... 1 (branch)
16÷3 = 3 (bundled) ... 1 (branch)
10÷2 = 5 (beam)
These flowers can be tied into three bundles at most.
Tip: Because seven chrysanthemums, three Chinese rose flowers and two tulips need to be tied into a big bundle, they can't be tied into a bundle as required, so they can only be tied into three big bundles.
29. A train was supposed to arrive at 1 1: 20, but now it will be 25 minutes late. What time does it arrive?
1 1: 20+25 = 1 1: 45
A: Here we are 1 1: 45.
30. Take a merry-go-round in the amusement park. How much does it cost to ask 9 people for each 2 yuan? 10 How many people are there?
2×9 = 18 (yuan)
2× 10 =20 (yuan)
Answer: 9 people need 18 yuan.
10 people want 20 yuan.