Convert the dollar amounts to cents to make the math easier.
$2.20 = 220¢
$2.35 = 235¢
The original price is 100%
The new price is x%
220/235 ≈ 0.93
Convert decimal into a percent by moving the decimal two places to the right and adding the % sign.
0.93 = 93%
100% - 93% = 7%
So, there was a 7% decrease in price.