Puzzle Book: Sudoku for Adults Volume 3Paperback, 3 March 2016

If there's one thing more challenging than your math book, it's a book of all numbers. The difference is that your textbook tells you if you have to divide, add, multiply or subtract equations in order to get the answers; but in this puzzle book you are left on your own. You have to figure out the reasoning behind the sequences. Can you do that?