The reason is that these cells are in text format!
So, change the format to General or Number, then enter the formula again.
Please note that the formulas in columns Q, O, N, and F are also in Text format!
So you have to convert them as well.
Please note that if you have a formula in a cell, and this formula refers to a cell formatted in text, this cell will become infected and will become like the format of the cell to which the formula refers!