Class name, student number score

Fill in the blanks. (16)

1. Please write five consecutive multiples of 12 ().

2. The common factor of all natural numbers is ().

3. The factor of 12 is (), the factor of 18 is (), the common factor of 12 and 18 is (), and the greatest common factor of12 and 18 is ().

The greatest common factor of 4.8 and 9 is (), and the smallest common multiple is ().

The greatest common factor of 24 and 5 1 is ().

5. The sum of two consecutive even numbers is 30, and their greatest common factor is ().

6.( 1) Fill in a number in brackets so that the greatest common factor of these two numbers is 1.

3 and () 8 and () 15 and ()

(2) Fill in a number in brackets so that the least common multiple of these two numbers is the filled number.

5 and () () and 12 () and 24

Second, choose. (8 points).

() of 1, 1 5,21is1.

A, multiple b, common factor c, maximum common factor d, minimum common multiple

2. A rectangle with a length of 6 cm and a width of 4 cm can be made into a square with a side length of () cm.

a、9 B、 12 C、 15 D、 16

3. a=3b, and both A and B are natural numbers greater than 0, so the least common multiple of A and B is ().

a、a B、b C、3 D、 1

There is a number less than 20, which is both a multiple of 3 and a multiple of 4. This number is ().

a、 18 B、 16 C、 12 D、 15

Fourth, the judgment question. (10)

1.3 and 5 have no common factor. ( )

2. If A is a multiple of B, then A is the least common multiple of A and B .. ()

3. The greatest common factor of two numbers must be smaller than both numbers. ( )

4. The least common multiple of two numbers must be greater than two numbers. ()www。

5. The greatest common factor and the least common multiple of18 are equal. ( )

5. Write the greatest common factor of each group directly. (12)

3 and 5 4 and 8 18 and 45

13 and 26 1 and 13 34 and 9 1.

6. Write the least common multiple of each group directly. (12)

6 and 12 7 and 8 8 and 12.

9 and 15 12 and 10 14 and 35.

Seven, solve the problem. (42 points)

1. There are two ropes, one is16m long and the other is 20m long. Now cut them into small pieces of the same length, each piece should be as long as possible, and there should be no excess. How long is each rope?

2. Cut a rectangular piece of paper with a length of 30 cm and a width of 25 cm into a square with the same size and as large an area as possible. How many pieces can you cut at least?

During the holiday, Xiaohong, Xiaoming and Liang Xiao all went to the library to borrow books. Xiaohong goes every 4 days, Xiaoming every 6 days and Liang Xiao every 3 days. On July 6, the three met for the first time in the library. When will they meet again?

4. Students take part in the running competition, with 5 or 2 people in each group. How many people are there?

5. Distribute 48 sweets and 38 chocolates to the same group of students. As a result, there were three sweets left and two chocolates missing. How many students are there in this group at most?

6. A rectangular piece of paper is 28 cm. The width is 22 cm, as shown on the right. Leave a 2 cm blank on the four sides of the paper, and then divide the middle rectangle into several identical squares on average. What is the maximum side length of a square?