Sudoku U: Senior Year

We’ll school you in sudoku! Find your grade, improve your play—and graduate to the next level. Sudoku professor Frank Longo has crafted five books with 300 sudoku each, which will take students from solving basics to super-hard, super-expert strategies. Try them and see how far you can go! You’re almost ready to graduate! If you’re looking for very hard puzzles, you’ll find them in Sudoku U: Senior Year. Every one of these 300 logical conundrums requires upper-level solving techniques.