Another example of where fairly basic math/arithmetic is useful - - - -
By the way - usually when a store says x% off the reduced price - the reduction is off the previously reduced price - not the original price
Example:
Original price: $100
35% off of $100 = (1.00 - .35) * 100 = $65.00
35% off of $65.00 = (1.00 - .35) * $65 = $42.25
Not: $100 *(1.00 - (.35 + .35)) = $30.00