Multiplication of large numbers is a method to find the least common multiple of several numbers. Specifically, double the largest number first, then double it to see if the obtained number is a common multiple of other numbers. If not, multiply it again and again, and then test it in the same way until the obtained number is a common multiple of these numbers.

The method of multiplying large numbers is to find the least common multiple, which is opposite to the fractional division of the greatest common divisor.