Sudoku Puzzles and Number Sequences contains 135 puzzles (60 Sudoku and 75 number sequences). All puzzles are graded to test your ability at different levels. The first chapter begins by introducing key strategies for solving Sudoku puzzles. It then follows with with very simple puzzles and ends with quite challenging puzzles. You will gain hours of fun and pleasure doing these types of puzzles. Where as Sudoku puzzles will test you logical thinking skills, Number Sequences will test your numerical IQ.