First, define the concept and fill in the blanks accurately.
1, according to 205×36=7360, write the product of the following questions directly.
2.05×36=( ) 20.5×36=( ) 0.36×205=( )
2.5.4 minus 1000 is (), minus1000 is 0.08, minus 50 minus () is 0.5.
3. Fill in ">" in ○. "<" or "=".
32×0.98○32 6.09×2○6.09 34×0.35○0.35
14×7.5○7.5× 14 6×7.04○7.04 18.9×5○5
4.1.8t = () kg 76g = () kg () cm = 0.5m.
900 ml = () liters 204 square decimeters = () square meters 8.75 meters = () millimeters.
5, a decimal point, first move the decimal point to the right, and then move the decimal point to the left by three places to get the decimal point is 0.27, the original decimal point is ().
6. Li Fang can make 45 crossings in 1 minute, Li Qiang's speed is four times that of her 1.4, and Li Qiang can make () crossings per minute.
7. The product of numbers A and B is 2.9. If the number A is expanded 10 times and the number B is expanded 100 times, then the product of the numbers A and B is now ().
8. The difference between numbers A and B is 9.9. Moving the decimal point of the number A to the left by one place is exactly equal to the number B, then the number A is () and the number B is ().
9. When Xiao Fang divides a number by 10, he takes the division sign as a multiplication sign, and the result is 3.2. The correct result should be ().
Second, deliberate and judge carefully.
1. To multiply a number by 10, just add a 0 at the end of this number. ( )
2.0.47 The result of enlarging 10 times is the same as that of reducing 100 times. ( )
3. If the decimal point 1.02 is removed, the number will be expanded by 100 times. ( )
4. When the side length of a square is multiplied by 10, the area is also multiplied by 10. ( )
5. If the product of two numbers is an integer, then these two numbers are not necessarily integers. ( )
Third, compare carefully and choose reasonably.
1, and the number less than 1 in the following formula is ()
a、67.2÷42 B、 18×0.2 C、4.68÷ 18
2. The quotient of numbers A and B is 7.5. If the number A is expanded by 10 times, the quotient of the number B should be ().
A, expand 10 times b, shrink 10 times c, unchanged.
3. If 2.8××□+7.2×□ = 50.8, you should fill in the □ sign ().
a、0.508 B、5.08 C、50.8