Nine numbers were used. Where 1 appears on the page number 1 times.
Page numbers consisting of two digits are: 10, 1 1, 12, ..., 99;
2*90= 180 numbers are used, in which 1 appears on the page number 10+8= 18 times.
The three-digit page numbers are: 100,10/,102, ..., 14 1';
3*42= 126 numbers are used, in which 1 appears 2*(9+4)+3*9+4=57 times in the page number.
The math book has 14 1 page. In the page number of this book, ask:
* * * Use a number of 9+2*90+3*42=3 15.
1 appears on the page number 1+ 18+57=76 times.