Trade score cards with your opponent. You keep score for your opponent in golf, including in high school play.
Count the number of strokes your opponent uses to get the ball in the hole per round. A stroke is counted every time the opponent swings at the ball.
Write the number of strokes on the card and then add them all together at the end of the game. Keep track of your own score as well so you can verify what your opponent records is accurate.
Verify the score on your scorecard that the opponent wrote down is accurate before writing your name on the top of the card and turning it in. The player with the lowest score wins.