Multiplication

From Wikipedia

Multiplication is an arithmetic operation for finding the product of two numbers.

With natural numbers, it returns the number of tiles in the rectangle where one of the two numbers equals the number of tiles on one side and the other number equals the number of tiles on the neighbouring side.

With real numbers, it returns the area of the rectangle where the first number equals the size of one side and the second number equals the size of the neighbouring side.

For example, three multiplied by five is the total of five threes added together, or the total of three fives. This can be written down as 3 × 5 = 15, or spoken as "three times five equals fifteen." Mathematicians call the two numbers you wish to multiply "coefficients" together, or "multiplicand" and "multiplicator" separately. Multiplicand × multiplicator = product.

Multiplication between numbers is said to be commutative - when the order of the numbers does not influence the value of the product. This is true for the Integers (whole numbers), e.g. 4 × 6 is the same as 6 × 4, and also for the Rational numbers (fractions), and for all the other Real numbers (representable as the field in the continuous line), and also for Complex numbers (numbers representable as the field in the plane). It is not true for Quaternions (numbers representable as the ring in the four-dimensional space), vectors or matrices.

The opposite of multiplication is division.

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