I want to sum the columns of a row and display the sum in the last column. As shown in the example below sum of each row is displayed in column TOTAL            COL1    COL2    COL3    COL4    TOTAL    ROW1     4       6       2        1      13    ROW2     2       2                2       6In the future, more columns may be added. So I want a formula for column TOTAL that can find the sum of range COL1 to TOTAL-1.
Formula for adding columns of a row till the last column in Google Spreadsheet
worksheet function;google spreadsheets;google documents