Integer multiplication
(1) Multiplies the first factor by the number on each bit of the second factor from the cell;
(2) Multiply by the number on the second factor, and the last digit of the number is aligned with the second factor;
(3) Add the multiplied numbers.
Multiply the number of digits of 25 and the number of digits of 10 by 4, and write the multiplication result below the corresponding number of digits. Then, multiply the number of digits of 25 and the number of digits of 10 by 2, and write the multiplication result below the corresponding number of digits. Finally, add the numbers on the corresponding numbers.
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 number "0" owned by the two numbers after vertical product is added.
4. Decimal multiplication should determine the position of the decimal point of the product according to the multiple of the decimal.
Multiplication:
1, multiplicative commutative law: a * b = b * a
2. Multiplicative associative law: a*b*c=(a*b)*c=a*(b*c)
3. Multiplicative distribution law: (a+b) * c = a * c+b * c; (a-b)*c=a*c-b*c