2. The number of multiples of a number is (), the smallest is (), the other is (), the number of factors of a number is (), the smallest is (), and the other is ().
3. Numbers like 0, 1, 2,3,4,5 ... are (), and numbers like -3, -2,-1, 0, 1, 2,3,4,5 ... are ().
The characteristics of multiples of 4.2 (), 5 () and 3 ().
5. Numbers that are multiples of 2 are called (), and numbers that are not multiples of 2 are called ().
6. A number has only two factors, 1 and itself. This number is called (). A number has other factors besides 1 and itself. This number is called (). () is neither a prime number nor a composite number.
7. A number is both a factor of 6 and a multiple of 6. This number is ().
8.4, 9 and 20, () is a multiple of (), and () is a factor of ().
9. A math textbook is on the table. At first, the front cover is facing up. After flipping 1 time, () face up; After two turns, () face up. The book was turned 50 times, () facing up, and after 2005, () facing up.
10. Prime number: 21=□ +□ =□×□ 8 = ()+()11. The product of two prime numbers is 35, namely () and ().
Second, I will find it. (4 points each, ***28 points)
1.50 is a multiple of 6 (), and the smallest is (). 100 is a multiple of 9 (), and the smallest is (). 100 is a multiple of 15 (), and the smallest is ().
2. Fill 20 numbers 1-20 in the appropriate circles below. (16)
Three, I know (judgment) (4 points)
1.2×4=8, where 8 is a multiple and 4 is a factor. ( )
2. The smallest integer is 0. ( )
3. Natural numbers are either odd or even. ( )
4. Natural numbers are either prime numbers or composite numbers. ( )
Fourth, see who can find it quickly. (12)
All factors of (1) 18: all factors of 2 1: factors of 18 and factors of 2 1:
(2) All factors of 24: all factors of 36: all factors of 24 and 36.
I am an expert in choosing letters. (10)
There are () factors a, 1 B, 2 C, 3 D, 4 E, 5 F, 6 (1)4. 5 has () factors.
(2) 1 has () factors. 9 has () factors.
(3) 15 has () factors. 12 has () factors.
(4) There are () factors 8. 16 has () factors.
(5) 17 has () factors. 18 has () factors.
6. I am an expert in group counting. (1, * * * 8 for each small question)
1. Choose two numbers from 5, 4, 3 and 0 to form a two-digit number, which meet the following conditions respectively.
(1) is a multiple of 3. (2) It is a multiple of 2 and 3 at the same time. (3) It is a multiple of 3 and 5 at the same time. (4) It is a multiple of 2, 3 and 5 at the same time.
2. Choose a number from 1, 5 and 6 and fill in the box to make the number meet the requirements of the topic.
(1) is a multiple of 2: 3□, 8□, 2□.
(2) It is a multiple of 3: 2□, 4□, 9□.
(3) It is both a multiple of 3 and a multiple of 5: 1□, 7□.
(4) Multiples of 2, 3 and 5 at the same time: □0, □20.
Seven, solve the problem. (19)
1. A number, which is both a multiple of 6 and a factor of 24. What could it be?
2. Grade five students need to plant 54 trees to participate in tree planting, and the number of trees in each row is required to be the same. How many different methods are there?
3. There are 48 fifth-grade students waiting in line to do exercises, requiring the same number of students in each row. How many different arrangements are there?
The grocery store sent 120 loaves of bread. If every two noodles are packed in a bag, can they be packed properly? If you put one in every three bags, can you finish it? If you pack a bag every five, can you finish it? (4 points)
The length of the classroom is 8 meters and the width is 6 meters. If the ground is paved with square bricks with a side length of 2 meters, how many square bricks are needed? If each square brick is 30 yuan, how much does it cost? (6 points)