how can sum byte value in crystal report

Hi friends,
        I have a four column in sql table with bit datatype. i import this data into dataset for generating crystal report. in dataset their datatype is byte. when i generate report based on the result it show  1 or 0. now i want to sum all the column value to formula field as total. here i tried with addition, it doesnt support because that is not a int value. so how can add these value?