Problems needing attention in vertical multiplication calculation;

The last digit of two numbers should be aligned.

Try to write as many numbers as possible on it, and write as few numbers on it to reduce the number of multiplications.

Precautions:

When the divisor is a decimal, convert the decimal into an integer and remember to move the decimal point.

When the divisor is an integer, divide the divisor by the integer part of the dividend. If there is not enough division, the decimal point of quotient 0 and quotient is aligned with the dividend.

The divider is decimal division. First, the divisor should be converted into an integer according to the law of quotient invariance, that is, the dividend and the divisor should be multiplied by 10, 100, 1000 at the same time, and the decimal point of the quotient should be aligned with the decimal point of the dividend.