Method:

1. Each digit of three digits is multiplied by the digit of two digits, and the last digit of the digit is aligned with the digit of two digits.

2. Multiply each digit of three digits by the number on the tenth digit of two digits, and the last digit of the number is aligned with the tenth digit of two digits.

3. Add the products multiplied twice.

Multiplication definition:

Multiplication is a shortcut to add up the same numbers. The result of its operation is called product, and "X" is the symbol of multiplication. From the philosophical point of view, multiplication is the result of qualitative change caused by additive quantity. The multiplication of integers (including negative numbers), rational numbers (fractions) and real numbers is a systematic summary of this basic definition.

Name:

"×" is a multiplication sign, the numbers before and after the multiplication sign are called factors, "=" is an equal sign, and the numbers after the equal sign are called products.

Reading:

In the current textbooks, only "multiplication" is said, not "multiplication". Pay attention to the difference between division and division.

Multiplication law and its calculation method;

Operating rules:

Integer multiplication meets the following requirements: exchange law, association law, distribution law and elimination law. With the development of mathematics, the object of operation has developed from integer to more general group. Intra-group multiplication is no longer needed to satisfy the commutative law. The most famous noncommutative example is the quaternion group discovered by Hamilton. But the law of association is still satisfied.

Calculation method:

The common methods of using pencil and paper multiplier need a small number (usually any two numbers between 0 and 9) to store or query the product multiplication table, but a farmer multiplication algorithm does not need it.

Multiplying a number with multiple decimal places is troublesome and error-prone. The universal logarithm was invented to simplify this calculation. The slide rule allows numbers to be quickly multiplied by about three digits of precision. Since the early 20th century, mechanical calculators, such as Marchant, have automatically multiplied as many as 10 digits. Modern electronic computers and calculators greatly reduce the need for manual multiplication.