The greatest common divisor of 2.4 and 28 is (), and the least common multiple is ().

3. The least common multiple of three prime numbers is 165, and these three numbers are ().

4. A number has only () two divisors, and this number is called a prime number.

5. Divide () into several parts on average, and the number representing such a part or parts is called a score.

7. Fill in the appropriate score in () below.

25cm = () m 15000m2 = () ha。

1 ton 600kg = () ton 1 10 second = () minutes.

1400 ml = () 8 months = () years.

125 cubic centimeter = () liter = () cubic decimeter.

8. put ">"

9. True score () False score.

Second, the judgment (6 points)

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

2. The least common multiple of two numbers must be divisible by these two numbers. ( )

3. The product of prime number and prime number is still prime number. ( )

4. All even numbers are composite numbers. ( )

5. The commutative law and associative law of integer addition are also applicable to fractional addition. ( )

Three. Choice (8 points)

1. 1-20 has () which is both complex and odd.

A. 1

2. Put 5g of sugar into100g of water, and sugar accounts for () of sugar water.

There is ().

A.5 B.6 C.7

A. greater than B. less than C. equal to

Four. Calculation (3 points for each question, *** 12 points)

Verb (abbreviation of verb) solves the following equation (3 points for each question, *** 12 points).

③0.4×6+3x=4.8 ④9x-2.7÷0.03=0

Six, application questions (5 points per question, ***40 points)

1. There are 49 students in one class, including 24 boys. What percentage of boys are in this class? What percentage of girls are in the class?

M, how long is the third paragraph?

3. There is a swimming pool with a length of 25m, a width of 12m and a depth of1.4m. How many square white tiles do you need?

The second week is 0.7 kilometers more than the first week. How many kilometers will it take to complete?

This cuboid reservoir has 2 100 cubic meters of water. This reservoir is 50 meters long and 20 meters wide. How deep is it?

6. The school sent 7.6 cubic meters of sand and spread it in a bunker 5 meters long and 3.8 meters wide. How thick can it be laid?

7. A water conservancy engineering team repairs ditches 125m every day for the first four days and 134m every day for the last three days. How many meters of canals does this engineering team build on average every day?

8. The shape of the cornfield is shown on the right. How many square meters is its area?

1. Fill in the blanks (65438+ 0 for each blank, ***25)

1, seven numbers 1, 2,3,4,21,19,53,87, () is a prime number, () is a composite number, () is both an odd number and a composite number, and () is neither a prime number nor a composite number.

2. The largest two-digit number divisible by 2, 3 and 5 at the same time is (), and its prime factor is ().

3. Xiaohong makes tea for 2 minutes, boils water for 20 minutes, washes teacups for 2 minutes, 15 minutes buys tea and makes tea for 3 minutes. Xiaohong needs at least () minutes.

4.A, B and C are all prime numbers, number A = A× B, number B = A× B× C, the greatest common divisor of numbers A and B is (), and the least common multiple is ().

5. 10.75 cubic decimeter = () cubic decimeter () cubic centimeter

7.5 cubic decimeter = () liter = () ml

6. The total side length of a cube is 36 decimeters, its surface area is () square decimeters and its volume is () cubic decimeters.

7, 500 ml of medical alcohol per bottle, 120 bottles of alcohol () liter, if there is 3.5 cubic decimeter of alcohol, you can put it in the bottle ().

8. The base area of a cuboid is 24 square centimeters, the height and length of the base are 4 centimeters, its volume is () cubic centimeters, and the width of the base is () centimeters.

9.a and B are prime numbers. Their greatest common divisor is () and their least common multiple is ().

10, the surface area of a cube is 96 square decimeter, and its volume is () cubic decimeter.

1 1. A production team must process a batch of parts. Originally planned 15 days to complete the task, 50 pieces were actually done every day, and the task was completed three days ahead of schedule. Actually, I finish () every day.

12 and a number divided by 2, 3 and 5 respectively are all 1, so the minimum number is ().

13, two Xiaohua Mall can catch two fish in two hours. According to their fishing techniques, if you want to catch 10 fish within 10 hours, you should go to () Xiaohua Mall.

Second, multiple-choice questions (2 points for each question, ***20 points) (choose the correct serial number and fill in the brackets)

1. 1280 needs at least a few digits to be divisible by 3. ( )

( 1) 1 (2)2 (3)4

2. Make two cuboid frames with two equal iron wires, and then these two cuboids ()

(1) Equal surface area (2) Equal volume (3) Both surface area and volume are not necessarily equal.

3 has () divisors. 70.

( 1)5 (2) 8 (3)4

4. If x is divisible by 13, then x is ().

(1) 26 (2) 13 (3)1or13

5. The sum of prime numbers within10 is ()

( 1) 17 (2)25 (3) 19

6,36 equals 4 and 9 ()

(1) times (2) least common multiple (3) common multiple

7. If a means b = 7, then ()

(1) a must be divisible by B. (2)a must be divisible by B. (3)b must be a divisor of A.

8. A long rice cooker can hold water 3 ()

(1) l (2) ml (3) m3

9. Merge two cubes with side length of 1 decimeter into a cuboid, and the surface area of the merged cuboid () is the sum of the surface areas of the original two cubes.

(1) greater than (2) less than (3) equal to

10. Of the following four sentences, the correct one is ().

(1) Two cubes with the same surface area have the same volume.

(2) Two prime numbers have no common divisor.

(3) A number is a multiple of B number, and A number must be a composite number.

(4) Even numbers are composite numbers.

Iii. Simple calculation (12)

1、 15.39×4.62+53.8× 1.539 2、9.98×97+29.94 3、 1 1 1 1÷25

Four, the application problem (1 to 3 questions each 6 points, the rest each 5 points, ***43 points)

1. How many square decimeters of iron does it take to make a cuboid iron water tank with a cover whose length, width and height are 8 decimeters, 6 decimeters and 5 decimeters respectively? What is the volume of this box?

2. How many liters of water can a rectangular iron drum with a width of 2.5 decimeters and a height of 35 centimeters hold?

3. An auditorium is 20m long,15m wide and 8m high. It is necessary to paint the ceiling and surrounding walls of the auditorium, excluding the area of doors and windows 120 square meters, with an average paint of 0.45 kg per square meter. How many kilograms of pigment does a * * need?

4. A cube fish tank with a length of 12 cm is filled with water. Pour water into a cuboid fish tank with a length of 18 cm and a width of 10 cm. How deep is the water?

5. There are three iron wires, one is 24m long, the other is 32m long, and the other is16m long. Divide them into small pieces of the same length. How long is each piece?

6. Children divide apples. If everyone is divided into two, there is 16. If everyone is divided into five parts, it will be less 14. How many children are there?

7. Lingling is 1 1 years old, and grandpa is 74 years old. No matter how many teenagers there are, Grandpa is four times as old as Lingling.

8. Three cows and six sheep graze 93kg a day, and six cows and five sheep graze 130kg a day. How many Jin of grass does each cow eat more than each sheep every day?

Last/better/previous/last name

/stjj/stwnj/index.htmlThere are many natural numbers A and B, the greatest common divisor is 7, the quotient obtained by dividing A by B is L, and B is _ _ _ _.

Analysis: If (a, B) =7 and A: B =, then the number of b =7×8=56.

2. There are 1 15 candy, 148 cookies and 74 oranges in the kindergarten, which are distributed to the children in the big class on average. As a result, there are 7 sweets, 4 biscuits and 2 oranges. How many children are there in this big class at most?

Analysis: According to the meaning of the question, it is not difficult to see that the number of children in this large class is the greatest common divisor of 1 15-7 = 108, 148-4= 144, 74-2=72. So this big class has at most 36 children.

Grandpa said to Xiaoming, "I am seven times your age now, six times your age in a few years, five times, four times, three times and two times your age in a few years." Do you know the age of Grandpa and Xiaoming now?

Analysis: The ages of Grandpa and Xiaoming are changing with the passage of time, but their age difference remains the same. Grandpa's age is now seven times that of Xiaoming, indicating that their age difference is a multiple of 6; Similarly, their age difference is a multiple of 5, 4, 3, 2, 1 It can be inferred that their age difference is a common multiple of 6, 5, 4, 3 and 2. [6,5,4,3,2] = 60, and the age difference between Grandpa and Xiaoming is an integer multiple of 60. Considering the actual situation of age, the age difference between grandpa and Xiaoming should be 60 years old. So now Xiaoming's age is 60 ÷ (7- 1) = 10 (years old).

Grandpa's age = 10×7=70 (years).

4. Given that the greatest common divisor of two natural numbers is 4 and the least common multiple is 120, find these two numbers.

Analysis: These two numbers are 4 and 120, or 8 and 60, or 12 and 40, or 20 and 24.

The sum of two natural numbers is 50, and their greatest common divisor is 5. Try to find out the difference between these two numbers.

Analysis: Two numbers can be 7,49 or 2 1, 35; Then the difference is 42, 14.

More than 20 questions can be edited by yourself.