There are many ways of calculating your discount and final purchase price. One way is to multiply 644 dollars by 20 percent, and then divide the answer by one hundred, then deduct that result from the original price. See illustration below:
+ Purchase Price = $644 - Discount (644 x 20)/100 = $128.80 = Final Price 644 - 128.80 = $515.20
Thus, a product that normally costs $644 with a 20 percent discount will cost you $515.20, and you saved $128.80.
You can also calculate how much you save by simply moving the period in 20.00 percent two spaces to the left, and then multiply the result by $644 as follows: $644 x .20 = $128.80 savings.
Furthermore, you can get the final price by simply deducting .20 from 1 and multiplying it by $644 as follows: (1 - .20) x $644 = $515.20 final price.
