Sometimes when you import data from another source, it may appear to Excel to be text rather than numbers. This is easily corrected with the function. Suppose that one or more of the cells of data in Total Cost Model was showing as text. If this were the case, Excel would not be able to do calculations with that data. Go to the cell C$3$ and type $=$Value$($B$3).$ This would convert the first cell of text to data. Use the fill$-$handle to copy this down to the other $2$ rows.