The largest two digits are multiplied by the largest one digit: 99x9 = 89 1, and the smallest two digits are multiplied by the smallest one digit 10x0 = 0. The partial product between Zhen and that is a two-digit number, such as 22x3 = 66.

Therefore, the product of two digits multiplied by one digit in the third grade math problem may be two digits, three digits or one digit.

Because the largest two digits are 99, the largest one digit is 9, and the product is 89 1, three digits.

The minimum number of digits is 1, the minimum number of digits is 10, and the product is 10, with two digits.

So when two digits are multiplied by one digit, the product may be three digits or two digits.

Extended data:

Four problems in vertical calculation of multiplication;

1, the last digit of two numbers should be aligned.

2. Write as many numbers as possible above, and write as few numbers as possible below to reduce the times of multiplication.

3. If there is a "0" at the end of both numbers, the last digit of the number can only be aligned before the "0" when writing vertically, and finally the numbers of the two royal buildings can be added to the back of the vertical product.

4. Decimal multiplication should determine the position of the decimal point of the product according to the multiple of the decimal.