How do I solve 394 × n = 3.94

You divide both sides of the equation by 394.
it is because you are trying to isolate "n" on one side and since it is multiplication on the "n x 394", you want to do something to get rid of 394 which is to divide it by 394.

multiplication and division is like the opposite of each other, like subtraction and addition.

When you do something to one side of the equation, you have to do it to the other side. so now you have "394 / 394 x n = 3.94 / 394"

since 394 divided by 394 equals to 1, now you have "1 x n = 3.94 / 394" 

whatever multiply by 1 equals to one, so no need to multiply n by 1. now you are left with the equation: "n = 3.94 / 394"

now you have to solve 3.94 / 394. if u plug it into the calculator, you should get an answer of 0.01

therefore "n = 0.01"

Best answer that i found on yahoo ok   set :   x= length of 2nd piece in cm  x- 3= length of 1st piece in cm  x-4= length of 3rd piece in cm  then since you know they all came from the 20 cm ribbon you add them together and set them equal to 20x+ x-3 +x-4 = 20  3x - 7= 20  3x= 27  x= 9  the shortest piece is the third piece which is x- 4  x-4  9-4 = 5  the length of the smallest piece is 5 cm.  the other lengths are  9 cm  6 cm