Form calculation is not working

Hello - on page 3 of this form, I would like to add the total of the check box options with the drop down tour options below. Can you look at the formula I entered for the widget on that page to see where my error is? Thanks so much!

I have checked the calculation formula of the Total amount due in Page 3 and see that some of the elements in the calculation are being used as String. 

Also, please check the calculation values of the checkbox field from the same page since there are 3 options listed and 4 calculation values being used. Please try changing the String elements to Number in the calculation field just by clicking on them so that they turns to Black and the formula on the form should be working fine. 

 Please let us know if you need any further assistance. We will be happy to assist.