Many states and cities levy a sales tax on retail purchases. The sales tax is determined by finding a percentage of the purchase price. The percentage of tax called the tax rate varies between different cities and states.

If the sales tax is 6% and a $10.00 purchase is made, the sales tax is $10.00*6/100 or $0.60. The total sales price is $10.00+$0.60=$10.60.