it starts off as 2:3 right? so the 3 is light soy sauce. if you want to turn the right soy sauce into 1 cup you have to divide 3 bye 3 which gives you one. then you also divide by 3 on the other side. that would be 2 divided by 3. 2 divided by 3 is the same as 2/3. so your answer is 2/3.
