>>16769110
>>16769166
Everytime you have two positive integers (a, b) in multiplication you aren't making “a large sum”, you are making a square in a vertical and horizontal plane. Sum is an one-dimensional operation, working on a line, while multiplication is a two-dimensional operation. Make a square out of four squares in the y-axis and four squares in the x-axis, you'll find that makes 16. Make a square out of three squares in the y-axis and five squares in the x-axis and you'll find that makes 15. This question is almost the basically principle behind completing the square.
