Okay, well, you could say that: Kylie bought a pair of shoes for $50. She was happy with them until the next week, when she noticed that same shoes were now on sale for 20% less. How much would Kylie have saved if she had known about the sale and waited to buy her shoes then?
Answer: $50 shoes.
10% of $50 is is $5, so 20% of $50 is $10.
She would have saved $10 by waiting.