2. A cuboid has at most () faces with the same area and at most () sides with the same length.

3. Among the ten natural numbers from 1 to 10, odd numbers have (), even numbers have (), prime numbers have (), and composite numbers have (), which are neither prime nor composite numbers.

4. The decimal unit is (), and it has () such decimal units. Adding () such decimal units is the smallest odd number.

5.50 square centimeters = () square decimeter

16 hour = () 250 ml per day = () liter.

6. Divide the 7-meter-long wire into 8 parts, each with a length of 7 meters () and each with a length of () meters.

7. The prime factor of decomposition 24 is ().

8. The smallest prime number is (), and the smallest composite number is ().

9. The greatest common divisor of 15 and 16 is (), and the least common multiple of15, 30 and 60 is ().

Second, judge whether the following statement is correct. (4 points)

1, 1 meter is 4 meters long. ( )

2. A cube with a length of 6 decimeters has the same surface area and volume. ( )

3. All even numbers are composite numbers. ( )

4. There is at least one prime number in two prime numbers. ( )

Third, choose the serial number of the correct answer and fill it in brackets. (4 points)

The prime factor of 1. decomposition 18 is ().

① 18=3×6 ② 18=2×3×3 ③ 18= 1×2×3×3

2. The sum of two odd numbers must be ().

① Prime number ② Odd number ③ Even number

3, and these two scores ().

① Equal in size ② Same in meaning ③ Same in fractional units.

Fourth, the application problem. (36 points)

1. It takes several hours for Master Wang to process a machine part, but it takes several hours for Li Shifu. How many hours does Li Shifu spend less than Master Wang?

The road team built a section of road, the first day was full length, and the second day was full length. How much is left in the whole length?

A car travels 30 kilometers in 24 minutes. How many kilometers per minute do you drive on average? How many minutes does it take to drive 1 km on average?

The side length of a cubic iron block is 3 decimeters, and it is known that the iron block weighs 7.8 kilograms per cubic decimeter. How much does this cubic iron block weigh?

A rectangular bunker is 5 meters long, 3 meters wide and 0.5 meters deep. How many square meters is this bunker? How many cubic meters of yellow sand do you need if the bunker is full of yellow sand?

6. A 6-meter-long cubic glass jar. Fill it with water, and then pour all the water into a rectangular water tank with a bottom area of 54 square decimeters. How high is the water level in the water tank?