The price of a digital camera sold in stores is $129. it is sold on ebay for $65. what is the percent decrease from the store's price to the online price

What i did is multiply 65 times 100, and divided by 129, 
(65)(100)= 6500
6500/129= 50.3

then to check i did multiply 50.3 by 129, and divided by 100
(50)(129)= 6450
6450/100= 64.50 

I don't think its 50% or either 51%, because 50% gives something less than 65, and 51% gives more than 65. So maybe its in the middle.

to get the right percentage do 50.1 or 5.6 times 129, and then divide by 100