Today, price of a new cell phone is $129. in 2000, the price of a similar cell phone was $240. what is the percent of change in that price of a cell phone from 2000 to today?

To figure this out, you put how much money you changed from then to now as your numerator. So you would have - 111 over your original price, which is 240. now, all you have to do is do negative 111:240 which should be 0.4625. then, to find your percent, all you have to do is move your decimal over to places to the right. 46% decrease!