There is a 48-page book, with one missing in the middle. Xiao Ming adds up the page numbers of the remaining books to get 1 13 1. The teacher said that Xiao Ming made a calculation mistake. Do you know why? 1+2+3+...+48= 1 176

1 176- 1 13 1=45=22+23

This question is a bit embarrassing.

The title should default to odd numbers in front and even numbers in the back of each page.

The positive and negative sides are two continuous natural numbers, the odd number is small and the even number is large.

According to Xiao Ming's calculation, the two page numbers of the torn book are 22 and 23, so it is wrong.