At the end of your function,
return total_value_in_a_round
At the end of OneRound, return the score to the calling program by combining the last two lines:
return userscore()
In your main program, set up a loop to play 5 times, and keep a running sum of the score:
total_score = 0
for round in range(5):
total_score += OneRound()
print "Your score for 5 rounds is", total_score
solved How to add up all the scores from each round to get a total score