Just scratch out a score card on a piece of paper to keep track of how many 5's 4's and X's for each end and total them up when you're done (i.e. total number of 5's X 5, plus total number of 4's X 4, and total number of X's)

end |5's |4's |X's
1| ||
2| | |
3 | | |
-
-
12| ||
______________
Total