Anecklace regularly sells for $18.00. the store advertises a 15% discount. what is the sale price of the necklace in dollars

I can solve with 2 methods:

I. Because the discount is 15 % of 18 $ , the price will be (100-15=85) 85 % of 18 $
18*85/100= 15,3 $ ( the sale price)

II. The discount is 15 % of 18$
15*18/100= 2,7$  ( the discount)
then I decrease it from the regularly price
18$-2,7$=15,3 $ (the sale price)

Personally I believe the first is an easier method.
I hope you understand and you can apply this in every similary problem.