= IF(a 1 & lt； 0，A 1-0.5，A 1+ 1)

In this formula, if your value is in cell A 1, the formula will check whether the value of A 1 is less than 0, if so, subtract 0.5 point, if not, add 1 point.

Next, let me help you understand the calculation method:

Let's assume that the scores of five schools are 70, 80, 60, 75 and 85 respectively. Then their average score is (70+80+60+75+85)/5 = 74.

Then, we can calculate the difference between each family's score and the average score, and then add and subtract points according to the rules. For example, the score of the first family is 70, and the average score is -4, so there is no deduction; The second score is 80, which is 6 points different from the average score, and 5 points will be deducted; The third score is 60 points, which is-14 points different from the average score, and 2.5 points will be deducted; The fourth place score is 75, which is different from the average score 1 point, and no points will be deducted; The fifth score is 85, which is different from the average score by 1 1 point, so 5 points will be deducted.

Finally, after deducting the corresponding scores from each family's scores, add them up and divide them by 5 to get the final average score.