Calcudoku (also known as "Mathdoku") is a mathematical and logical puzzle loosely similar to Sudoku. The objective is to fill the grid in with the digits 1 through N (where N is the number of rows or columns in the grid) such that: - Each row contains exactly one of each digit. - Each column contains exactly one of each digit. - Each bold-outlined group of cells (block) contains digits which achieve the specified result using the specified mathematical operation: addition (+), subtraction (-), multiplication (×), and division (÷). - Unlike Killer Sudoku, digits may repeat within a block.

3D Sudoku is the ultimate challenge for an fan of Sudoku puzzles. With three times as many numbers than normal Sudoku, follow the colored lines and complete the rows and boxes with the numbers 1-9. If youre a fan of Sudoku, then you will love this great new collection of over 300 ultra challenging 3D Sudoku puzzles!

It's only logical--boost your brainpower with 150 logic puzzles for adults. It's time to give your mental muscles a real workout! Stuffed full of clever and cunning challenges, this collection of logic puzzles for adults is perfect for puzzlers looking to prove (and improve) their skill. Featuring a variety of puzzle types--including Sudoku, Masyu, Logic Grids, and Nonograms--these easy-to-understand (but tough-to-solve) puzzles will help keep your mind sharp as you remain engaged and entertained for days to come. Brainpower on! This exciting book of logic puzzles for adults includes: 150 puzzles, 1 big collection--Find a plethora of logic puzzles for adults all packed into one portable package. True brain-busters--Stretch your abilities with puzzles that are designed to be tough--even for master puzzlers! Plenty of options--Banish boredom with several types of puzzles, including math-focused Calcudoku and innovative Cryptic Puzzles that require both code breaking and creative thinking. Test your mental acumen with this collection of truly challenging logic puzzles for adults.

This book contains AI Escargot, the world famous sudoku puzzle which became the most difficult sudoku puzzle known in 2006. There are also several hints for solving AI Escargot in the shortest and most logical way. In addition, the book has 166 other sudoku puzzles in 11 categories. This makes it very convenient to find out your own level and to learn more! The author, Arto Inkala, is a puzzle creator and a doctor of science in the field of applied mathematics.

Welcome to this huge collection of Number Searches, with 1000 puzzles! The rules of Number Search puzzles are simple: find the listed numbers in the grid. They can be laid out in any of the 8 directions: horizontal, vertical, left diagonal, right diagonal and all those backwards, too! Thousands and thousands of numbers for you to find! Printed in large font, very easy to read the numbers! ENJOY! :) _______________________________________ number search, number searches, number search book, number searches book, number sleuth, number find, large print number search, number search large print, large font number search, number search large font, big print number search, number search big print, big font number search, number search big font, large print number search book, number search book large print, large font number search book, number search book large font, big print number search book, number search book big print, big font number search book, number search book big font, number sleuth book, number find book, find a number, find a number book, numbers in a grid

Can't get enough of Sudoku? This book is for you! It contains three hundred challenging and devilishly difficult Sudoku puzzles in a portable paperback. Features: - 300 hard Sudoku puzzles - Big grids for easy solving - Edited by legendary puzzlemaster Will Shortz

Kakuro is a puzzle type in which sums are given and solvers must deduce the numbers in the individual boxes. This title is suitable for hardcore kakuro devotees.

Based on the science that shows that people middle-aged or older who solve word games and brainteasers have a significant cognitive advantage over those who do not, 399 Games, Puzzles & Trivia Challenges is the illustrated game book specifically created to cross-train the brain. Here are 399 games to stretch, challenge, and push the reader, all of which stimulate the formation of neurons—literally, regrowing the brain. Plus they’re not only good for you, but just plain good—these games are fun. 399 Games, Puzzles & Trivia is a lively mix of challenges, riddles, and brainteasers—all vetted by a neuroscientist who specializes in aging brains and designed to work the six key areas of cognitive function that are vulnerable in normal aging: long-term memory, working memory, executive functioning, attention to detail, multitasking, and processing speed. The games are arranged from easiest to most difficult and are labeled according to which cognitive functions they exercise so they can be mixed and matched into a custom “workout.” In just 15 minutes a day, anyone can improve his brain’s strength, flexibility, and long-term health.

Watch out! These puzzles are mind melting! But if you dare, grab a pen and take on these two hundred all-new extra challenging puzzles. Features: 200 hard puzzles Big grids for easy solving Introduction by legendary puzzlemaster Will Shortz