1, carry multiplication rule: This is the most basic multiplication calculation method. Based on the decimal principle, it multiplies bit by bit and carries, and finally adds up to get the final result.

2. Standard vertical multiplication: also known as column vertical multiplication, it is a common multiplication calculation method. By arranging the multiplicand and multiplier bit by bit, multiplying them bit by bit, and finally adding all the results, the final product is obtained.

3. Russian multiplication: Also known as Oriental multiplication, it is a fast multiplication calculation method using addition and shift operations. Multiplier and multiplicand are repeatedly divided by 2 and rounded down, and the results are added together until the multiplier becomes 1. Finally, add the values corresponding to the multiplicand to get the final product.

4. Egyptian multiplication: an ancient multiplication calculation method based on the principle of multiplication and addition. By multiplying the multiplier all the time, observe the parity of the multiplier, decide whether to add, and finally add all the results to get the final product.

5. Matrix multiplication: In linear algebra, matrix multiplication is a common multiplication operation. Multiply two matrices according to certain rules to get a new matrix.

6. Equation multiplication rule: also known as the grouping multiplication rule, it is a method of decomposing the multiplier into smaller factors, multiplying them one by one, and then adding them. Through step-by-step multiplication, the larger calculation task is transformed into smaller calculation task, which improves the calculation efficiency.

The origin of cross multiplication

The origin of cross multiplication, also known as rectangular multiplication, can be traced back to ancient Assyrian and Babylonian cultures. This method performs multiplication by drawing a line between two numbers and counting the number of intersections on the line.

Cross multiplication is very common in daily life and is widely taught to students as a method of calculating multiplication. Although its specific origin is not clear, cross multiplication has been used in mathematics education and is considered as a simple and intuitive calculation method.