In order to show the page number of the total number of pages in the report generator the PageNofM system variable is used. This variable is a combination of system variables, such as the PageNumber and the TotalPageCount, i.e. it will print the page number on the total number of pages.
On the picture above the "Page 1 of 3" shows that the first page of three pages is available. The PageNofM depends on localization so it should be used very carefully.