Ok, after some googling, I think I understand a little better.
KI is about 76.4% of Iodide (I-) by weight. So when you dissolve a 1 gram of it in 1 ml of water to make SSKI , there is 764 mg of I-. But the amount of KI is still considered 1 gram and the I- is referred to as Iodine as iodide.
Then comes the amount in one drop from a dropper. If a drop contains 20 mg of iodine, then there should be about 26-27 mg of KI. Or, find n where n(0.764) = 20.