sales tax is the amount of tax per dollar, right? if a dollar is 1.00 then 8% of that dollar would be 0.08. now you have $12 dollars. you would multiple $12x.08, which would be the decimal $0.96. this will be so small because you are multiplying a whole number and a decimal. next, you take that $0.96 and add it to $12, getting $12.96. the total cost of an item that sells for $12 in a town with 8% sales tax would be $12.96.