This crossword puzzle book contains 100 puzzles. Each puzzle is slightly different. The puzzle itself is on one page with the tips on the following page. Answer key is in the page of the book, three per page. There was no such thing as the crossword puzzle in ancient times. But the Greeks, Romans, and other peoples had a kind of word game called the word square that would lead to the invention of the crossword puzzle many years later. A word square is a group of three or more words arranged in a square, so that the words read across the same as they read down. During the 19th century, word squares appeared in newspapers and magazines in England and America. But they were printed in their completed form, not as a puzzle that the reader had to complete. Then in 1913, an editor at a newspaper, the New York World, was constructing a word square for a puzzle page. But he decided to make a puzzle out of it by leaving the words for the readers to fill in. And instead of having the words read down the same as they read across, he let the "across" words form different words when read "down." Called a "word-cross" at first, this was the world's first crossword puzzle. Crossword puzzles caught on quickly in America and England, and by the 1920s, they were in almost every newspaper in this country. Crossword puzzles are now the number-one indoor pastime in the United States, more than 30 million Americans do crossword puzzles regularly! The largest crossword puzzle ever constructed had 5,553 words!