1、 The divisor of 1.54 is (), in which the odd number is (), the combined number is (), the prime number is (), and the even number is () 2. "2 / 3 of 12 chickens", here () is regarded as unit '1'. 2 / 3 means that the unit '1' is divided into () parts averagely, taking () parts, and "2 / 3 of 12 chickens" is () chickens 3. Three continuous natural numbers, the middle one is a, and the other two are (), () The greatest common divisor of 4.20 and 24 is () and the least common multiple is () In 5.1 and 4 / 5, there are () 1 / 5, and 8 1 / 4 are () 6. The unit of fraction is 1 / 4. The sum of all true fractions is () 7. Fill in the appropriate unit name or number in brackets 86 CC = 0.086 () 1.8 m3 = () l 8. The maximum three digits divisible by 2, 5 and 3 at the same time are () 9. Fill in a number in 324 () so that the number has a factor of 2, a multiple of 5, and can be divided by 3 2、 Judgment questions 1. If a number can be divided by 15, it must be divided by 3 and 5 at the same time 2. The fraction whose numerator is less than the denominator is true, and the fraction whose numerator is greater than the denominator is false 3. Multiply or divide the numerator and denominator of a fraction by the same number (except zero), and the unit of the fraction remains unchanged 4. The volume of a 400 cubic centimeter thermos cup should be smaller than 400 ml 5. Both a and B are natural numbers. If a △ B = 7, then the greatest common factor of a and B is 7 6. Fractions with the same denominator can be added or subtracted directly because their fractional units are the same 3、 Practical questions 2. Xiaohong's family bought a new goldfish tank with a side length of 4 decimeters on the bottom and 30 liters of water. How deep is it? 3. Two cuboids of equal volume are stacked to form a cuboid with a height of 12 cm. What is the surface area of the cuboid? What is the surface area of the newly stacked cuboid?

1、 The divisor of 1.54 is (), in which the odd number is (), the combined number is (), the prime number is (), and the even number is () 2. "2 / 3 of 12 chickens", here () is regarded as unit '1'. 2 / 3 means that the unit '1' is divided into () parts averagely, taking () parts, and "2 / 3 of 12 chickens" is () chickens 3. Three continuous natural numbers, the middle one is a, and the other two are (), () The greatest common divisor of 4.20 and 24 is () and the least common multiple is () In 5.1 and 4 / 5, there are () 1 / 5, and 8 1 / 4 are () 6. The unit of fraction is 1 / 4. The sum of all true fractions is () 7. Fill in the appropriate unit name or number in brackets 86 CC = 0.086 () 1.8 m3 = () l 8. The maximum three digits divisible by 2, 5 and 3 at the same time are () 9. Fill in a number in 324 () so that the number has a factor of 2, a multiple of 5, and can be divided by 3 2、 Judgment questions 1. If a number can be divided by 15, it must be divided by 3 and 5 at the same time 2. The fraction whose numerator is less than the denominator is true, and the fraction whose numerator is greater than the denominator is false 3. Multiply or divide the numerator and denominator of a fraction by the same number (except zero), and the unit of the fraction remains unchanged 4. The volume of a 400 cubic centimeter thermos cup should be smaller than 400 ml 5. Both a and B are natural numbers. If a △ B = 7, then the greatest common factor of a and B is 7 6. Fractions with the same denominator can be added or subtracted directly because their fractional units are the same 3、 Practical questions 2. Xiaohong's family bought a new goldfish tank with a side length of 4 decimeters on the bottom and 30 liters of water. How deep is it? 3. Two cuboids of equal volume are stacked to form a cuboid with a height of 12 cm. What is the surface area of the cuboid? What is the surface area of the newly stacked cuboid?

Fill in the blanks
The divisors of 1.54 are (1,2,3,6,9,18,27,54), among which the odd number is (1,3,9,27), the combined number is (6,9,27,54), the prime number is (2,3), and the even number is (2,6,18,54)
2. "2 / 3 of 12 chickens", here (12 chickens) is regarded as unit '1'. 2 / 3 means that the unit '1' is divided into (3) parts averagely, and (2) "2 / 3 of 12 chickens" is (8) chickens
3. Three continuous natural numbers, the middle one is a, and the other two are (A-1) and (a + 1)
The greatest common divisor of 4.20 and 24 is (4), and the least common multiple is (120)
In 5.1 and 4 / 5, there are (9) 1 / 5, and 8 1 / 4 are (2)
6. The unit of fraction is 1 / 4. The sum of all true fractions is (1.5)
7. Fill in the appropriate unit name or number in brackets
86 CC = 0.086 (cubic decimeter) 1.8 m3 = (1800) l
8. The maximum three digits divisible by 2, 5 and 3 are (990)
9. Fill in a number in 324 (0) so that the number has a factor of 2, a multiple of 5 and can be divided by 3
2、 Judgment questions
1. If a number can be divided by 15, it must be divided by 3 and 5 at the same time
2. The fraction whose numerator is less than the denominator is true, and the fraction whose numerator is greater than the denominator is false
3. Multiply or divide the numerator and denominator of a fraction by the same number (except zero), and the unit of the fraction remains unchanged
4. The volume of a 400 cubic centimeter thermos cup should be smaller than 400 ml. (√)
5. Both a and B are natural numbers. If a △ B = 7, then the greatest common factor of a and B is 7
6. Fractions with the same denominator can be added or subtracted directly because their fractional units are the same
3、 Practical questions
2. Xiaohong's family bought a new goldfish tank with a side length of 4 decimeters on the bottom and 30 liters of water. How deep is it?
30 / (4 * 4) = 1.875 decimeters
3. Two cuboids of equal volume are stacked to form a cuboid with a height of 12 cm. What is the surface area of the cuboid? What is the surface area of the newly stacked cuboid?
Edge length 12 / 2 = 6cm
The surface area of cube is 6 * 6 * 6 = 216 square centimeters
Cuboid surface area 6 * 6 * (6 * 2-2) = 360 square centimeter

All non-zero natural numbers are either prime numbers or composite numbers______ (judge right or wrong)

According to the number of factors, natural numbers can be divided into three categories: prime numbers, composite numbers and 1. Therefore, all non-zero natural numbers are either prime numbers or composite numbers

All natural numbers are either prime numbers or composite numbers______ (judge right or wrong)

According to the analysis: prime number and composite number are classified according to the number of factors of a natural number, because 1 has only one factor itself, so 1 is neither prime nor composite number. Therefore, all natural numbers are not prime numbers or composite numbers. This statement is wrong. So the answer is: wrong