To solve this problem, we need to figure out how much tax Peter will be paying, given that the tax rate is 10% and his purchase costs $66.30.
To do this, we must first convert 10% into a decimal. To do this, we must divide it by 100 (because it is a fraction out of a total of 100 percent), or simply move the decimal point two places to the left. Therefore, 10% = 0.10.
To find the tax amount, we must multiply the sales tax rate (10% or 0.10) by the purchase cost ($66.30). This gives us:
$66.30 * 0.10 = $6.63
Therefore, your answer is $6.63.
(A little tip: the method I used above can be used for any tax rates, but a trick for finding 10 percent of something is to move the decimal point of the cost one place to the left).
Hope this helps!