Once upon a time, before automatic scorekeepers, every bowler had to know how to keep score by hand. Each team member was expected to take turns keeping score at the score table. It is an old-time skill now, but it helps to know how to do it to check the accuracy of the computer.
In the first frame, enter the number of pins hit on the bowler's first throw to the left of the small box. Write the number of pins hit in the second throw in the small box, then the combined total in the space below. If the bowler marks, as in throws a strike or spare, leave the space below empty since it tracks the accumulative score. If the bowler throws a spare, put a / in the second box. If the bowler throws a strike, the frame gets an "X." Some old timers put an X over the entire box, but an X in the small box will do.
Fill in the other frames the same way. The top two boxes reflect what the bowler did in that frame while the bottom space shows the bowler's total game score. If the bowler goes the entire game without a strike or spare, use simple addition to get the final score. Spares and strikes require some additional math.
If the bowler threw a spare in the previous frame, add 10 to the number of pins she knocks down on her first ball in the new frame. Only the first ball counts as an addition to a spare. So, if the bowler had a spare in the first frame, then knocked down seven pins with her first ball in the second, and one pin on her second ball, her score is 18. If she gets another spare, write "17" in the blank space in the first frame. Leave the second one blank until the next frame.
If the bowler throws consecutive strikes, keep writing X in the frame. If the bowler throws two strikes and then gets eight pins and a spare in the third, add 10 plus 10 and 8 and the score for the first frame is 28. The score for the second frame is 48 since you added 10 for the strike in second and 10 for spare in the third. The running total will remain blank in the third frame pending the bowler's score in the fourth. If she gets another strike, you can add 10 and 10 again for a total of 68 in the third. If she rolls a 7 and 1, apply the spare rule. That would add 17 to the total from second for a score of 65 in the third. Since she missed a mark in the fourth, you can then add her total to the point. The extra eight pins would give her a score of 73 through four frames.
The 10th frame has a special scoring rule. If a player gets a spare, he gets one more throw. If he gets a strike on his first ball, he gets two more throws. If a player throws all strikes, including the two bonus throws, the player will achieve a perfect score of 300.