Im doing a lawn renovation for a property of 1200 sq ft. along with mulch installation. The original estimate has everything involved, materials and labor, listed and priced. The total should be 1160.00 , but the software (excell) spreadsheet I used, did NOT add all the subtotals, omitting one item at a cost 350.00. Therefore the total listed on the estimate is 790.00. Like I said, everything is listed, broken up into catagories with sub totals and then a grand total. What do you think I should do. Bring it to the customers attention, explain that its was a software mathamatica error, and ask for the correct amount?