1.35 and 7, (35) is divisible by (7), (35) is a multiple of (7), and (7) is a divisor of (35).

2. Both cuboids and cubes have (6) faces, (12) edges and (8) vertices.

3. The side length of the cube is 5dm. The sum of the sides of this cube is (60 )dm, its surface area is (150 )dm2 and its volume is (125 )dm3.

4. The sum of three consecutive odd numbers is 2 1, which are (19), (2 1) and (23) respectively.

5. Among natural numbers 1 ~ 20, the minimum composite number is (4), the minimum odd number is (1), the even number is prime number (2), and the odd number is composite number (9, 15).

7. The sum of the sides of a cuboid is 84cm, 8cm long, 7cm wide, (6 )cm high and the surface area is (146) cm2.

8.5 kg of sugar is divided into 6 portions, 5 kg (1/6) each and 5 kg (5/6) each.

9. Fraction, when X=( 1), is the decimal unit of this fraction; When X= (1 less than the denominator), it is the maximum true score; When X= (equal to denominator), it is the smallest false fraction; When X= (equal to denominator), its fractional value is 1.

10. expressed as a fraction:

25 minutes =( 5/ 12) 3080 kg =(3 2/25) tons.

3 o'clock =( 1/8) 4 square meters and 5 square decimeters =( 4 1/20) square meters.

Secondly, I will judge:

1. The numerator and denominator of the fraction are multiplied or divided by the same number at the same time, and the size of the fraction remains unchanged. (right)

2.3m 1/5 is as long as 3/5 of1m. .................................................... (right)

3. False scores are all greater than 1. ..................................................... (error)

If the volumes of two cuboids are equal, their surface areas are equal. ..... (Error)

5. The maximum approximate number and minimum multiple of18 are equal. ............................................. (right)

Third, I will choose:

1. A composite number has at least (a) factors.

A. 1 D. 2

2. When two prime numbers are multiplied, the product must be (c).

A. prime number B. odd number C. composite number D. even number

3. The side length of a cube is 6 cm, and the ratio of its surface area to its volume is (D).

A. same size B. large surface area C. large volume D. unparalleled

When the side length of a cube is doubled, its volume is expanded (8 times).

The fifth grade Olympic mathematics training in primary school.

Fill in the blanks (2 points for each 1 and 30 points for * * *).

1, and the sum of all three digits in a natural number is 5385 1.

2. Find the rules and fill in the numbers.

( 1) 1,3,2,4,3,(5 ),4;

(2)8 1,64,(49 ),36,(25 ), 16,9,4, 1;

(3)0, 1,4, 15,56( );

(4)0, 1,2,4,7, 12,20,( );

(5) 1,3,6,8, 16, 18,(36 ),(38 ),76,78;

(6)8,6, 16,3,24,2, 12,(8 );

4. A train is 360m long and runs at the speed of15m per second. It takes 40 seconds for the whole train to pass through a small cave. The length of this cave is

240 meters.

5. There is a column of numbers. The first number is 105 and the second number is 85. Starting from the third number, each number is the average of the first two numbers, so the integer part of the number 19 is 92.

6. The last digit of the sum of1×1+2× 2+3× 3+...+1991×1Yes.

7. A number multiplied by 6 times 8 equals its 8 times minus 6, and this number is 7.

Calculation problem (No.8 -65438 +00 problem 3 points, No.65438 +065438 +0-65438 +05 problem 5 points, ***34 points)

8、333×334+999×222

=333×334+333×666

=333×(334+666)

=333× 1000

=333000

9、200 1200 1×2002-20022002×200 1

=200 1200 1-200 1

=200 10000

10、( 1+ 1.2)+(2+ 1.2×2)+(3+ 1.2×3)+ ……+(99+ 1.2×99)+( 100+ 1.2× 100)

=[ 100+ 1+( 100+ 1)× 1.2]+......+[50+5 1+(50+5 1× 1.2]

=322.2+……+322.2

=322.2×50

= 16 1 10

1 1. In the figure, the area of triangle ABC is 52 square meters, the length of AC is 13 meters, DEC is a right isosceles triangle, and the area of triangle ABD is equal to the area of triangle ADC. Find the area of the shaded part ade. See the figure below:

12, the product of two natural numbers is 492, one of which is greater than 20 and less than 80. What are these two numbers?

A: 12 and 4 1.

13. The greatest common divisor of numbers A and B is 5, and the least common multiple is 120. Now the number a is 40. What is the number b?

A: 15

14. How many natural numbers from 1 to 100 are neither multiples of 5 nor multiples of 6?

A: 7 1

Application questions (6 points for each question, ***36 points)

15. Two trucks transport trees to the town. The first bus travels from the village to the town at a speed of 30 kilometers per hour, and the second bus travels from the village to the town at a speed of 40 kilometers per hour, one night 12 minutes. As a result, two people arrived at the same time How far is it from the village to the town?

12× 30 = 360km40-30 =10km360 ~10 = 36 hours.

36× 40 =1440km

Answer: 1440km

16, Xiaohua, Xiaoli and Xiaolin went from place A to place B. At 6 o'clock in the morning, Obana Xiaoli set off from place A together. Xiaohua was 5 kilometers per hour, Xiaoli was 4 kilometers per hour, and Xiaolin didn't set off from place A until 8 o'clock in the morning. By 6 pm, Kobayashi Takeru arrived at B at the same time. When did Xiao Lin catch up with Xiao Li?

5×2 = 12×5 = 60km 60 ~ 10 = 6km 4×2 = 8km。

8~(6-4)=4 hours 6+4= 10 hour

A: Morning 10

17, Xiao Wang walked along the service road next to the railway. A train came behind and passed Xiao Wang for 7 seconds. Train conductor 105 meter, speed 72 kilometers per hour. How many meters does Xiao Wang walk per second?

72~60= 1。 2 kilometers, 1. 2 km =1200m1200 ~ 60 = 20m

7×20 = 140m( 140- 105)~ 7 = 5m。

18. The still water speed of the ship is 20 kilometers per hour, and the river speed is 5 kilometers per hour. The ship spent eight hours going back and forth between AB and Hong Kong. How many kilometers are they apart?

A: 75 kilometers.

19, Zhang Hua bought a batch of vegetable oil and put it in barrels A and B, but neither barrel was full. If bucket A is poured into bucket B and bucket B is full, bucket A will be more 10 liter; If barrel B is poured into barrel A, barrel A can be filled with another 20 liters. The capacity of barrel A is 2.5 times that of barrel B. How many liters of oil did Zhang Huayi buy?

Answer: 22 liters of oil.

20. There are three plots A, B and C, with an area of 4 hectares, 8 hectares and 10 hectares respectively. The grass on the grass is as thick and grows as fast. Land A can feed 24 cows for 6 weeks, and land B can feed 36 cows 12 weeks. How many weeks can land C feed 50 cows?