What is 'multpution'????
If you means 'Multiplication'. Then taking an example.
If we have 3 + 3 + 3 + 3 . Instead of writing '+3' all the time, we shorten it to '-x4'.
Why '4' ? Becasue you are adding '3' four times over.
Sp 3 + 3 + 3 + 3 = 6 + 3 + 3 = 9 + 3 = 12; 3 X 4 = 12
Notice how much shorter it is to write '3 X 4' , than to write 3 +3+3+3.