VBA Apply Formula To Each Cell In Range

I'm using the code below to create sheets and copy pertinent data for each value found in column O on my data sheet.

Code:
Sub CreateSheets()
Dim WBO As Workbook
Dim ThisWS

[Code]....

What I'm now trying to do, is apply a formula for each cell, in columns C:N for each newly created sheet. The formula is 'The value of 100 minus the value of the cell'.

I've tried adding

Code:
cell.Value = 100 - cell.Value
to differing points of the script but I recieve a 'Type mismatch error.