Answer:
I would make sure to note keywords in the problem/question such as (percent) off, (percent) tax, etc. These words can determine if the original number will become higher or lower after the percent is applied to the original number. For example, if there is a price for a t-shirt of $15, and there is a tax of 13%, the original price will increase. On the other hand, if there is a sale for pants at the local department store and you are buying a pair of pants that cost $25 with the sale being 10% off, the price will decrease.