The answer is A, because A works out to be 30, and all other options work out to be 3.
This question comes from the mathematics midterm paper of the first volume of the fifth grade of Hebei Education Press. The knowledge points of the first volume of the fifth grade mathematics of Hebei Education Edition are:
1, the meaning of fractional division: know the product of two factors and one of them, and find the operation of the other factor. For example, 0.6:0.3 represents an operation to find another factor by multiplying the product of two known factors by 0.6 and multiplying one factor by 0.3.
2. Calculation method of decimal divided by integer (P 16): decimal divided by integer and then divided by integer. The decimal point of quotient should be aligned with the decimal point of dividend. The integer part is not divided enough, quotient 0, decimal point. If there is a remainder, add 0 and divide it.
3.(P2 1) Calculation method of division with divisor as decimal: first expand the divisor and dividend by the same multiple to make the divisor become an integer, and then calculate according to the rule that the divisor is an integer. Note: If there are not enough digits in the dividend, make up the dividend with 0 at the end.
4.(P23) In practical application, the quotient obtained by fractional division can also be obtained by "rounding" a certain number of decimal places as required.