Sort a list with a number of order# and values

say your order # list is in column A and your revenue is in column B. You can make a copy of your order numbers by highlighting column A and paste it to an empty column for instance column C. Then highlight the column and using the built in remove duplicates function remove the duplicates from that list.

Then using sumif =SUMIF(A:A,C2,B:B) you will get the totals for the order numbers. Sumif is (look at this column range,look for this item in that range, sum these values that appear across from that item in this column range)
Hope that helps.