The best thing to do is to find what 1% is, and you can do this by dividing 150 by 100. 150/100= 1.5 As you're looking for 6.5%, you've got to multiply 1.5 by 6.5 1.5*6.5= 9.75 You've then got to add 9.75 and 150 together 150+9.75= $159.75 Therefore, after the sales tax, the cost of the necklace is $159.75 Hope this helps :)