- Bowl. To calculate an average, you need some scores.
Add your scores. Say you bowl three games of 150, 181 and 136. Add those scores.
150 + 181 + 136 = 466
Divide by the number of games. In this example, you bowled three games, so you divide 466 by 3.
466 ÷ 3 = 155 1/3
- Round down. Bowling scores are typically rounded down, ignoring anything on the right side of the decimal point. In this case, your average is 155.