I am attempting to sort out an invoice spreadsheet to show VAT. Typically I have (For 8 items) a column showing a quantity, A description and a Unit cost. The next column has the formula =IF(SUM(P2*R2)>0,SUM(P2*R2),"")to calculate the extended cost of the item. (Quantity x Unit Cost)
After 8 sets of columns I have put in a formula that reads =SUM(S2+W2+AA2+AE2+AI2+AM2+AQ2+AU2)which adds up all the extended values - except it`s returning a #Value! Obviously I`ve made a mistake! Anyonepoint me in the right direction because I need to evaluate the VAT in a similar way.