it should be up to two to three A4 pages
A Thousand Acres by Jane Smiley has 384 pages.
A Thousand Lies has 304 pages.
A Thousand Tomorrows has 244 pages.
A Thousand Country Roads has 181 pages.
Cave of a Thousand Tales has 287 pages.
The Cold Six Thousand has 672 pages.
City of a Thousand Suns has 156 pages.
A Thousand Days - book - has 1120 pages.
Throne of a Thousand Years has 332 pages.
Ten Thousand a-Year has 514 pages.
400 Worlds Page Essay will roughly 1-2 pages long. The formatting option chosed will determine the variation of pages.