So, we need to get rid of the installation fee. That is not needed. Then, we divide 680 by 2 because the money pays for TWO years. 680 / 2 = 340 So then we divide 340 by 12 since there are 12 months in a year. 340 / 12 = 28.333... or 28. So, $28 is our answer. :)
