Like the rest of our bodies, our brains thrive on a nourishing, low-glycemic diet, regular exercise, plenty of sleep, and low stress levels, says Gary Small, MD, director of the Longevity Center at the University of California, Los Angeles and coauthor of 2 Weeks to a Younger Brain. And the more healthy activities we practice, the less likely we are to encounter memory problems. Kakuro Puzzles (Magworks Australia): Tougher Kakuro puzzles than the ones in the Puzzler publication, but the puzzle sizes are not as big. Also, there are usually a couple of puzzles that use a "doughnut logic" that I don't seem to get. I do Unique Rectangles, Box Line Reduction, and Set Reduction but I still feel as if I need to do a plain what-if guess by the end. Still, they are a good brain workout. This red square is missing a 7 as well as the red column. When 7 is placed in one of these slots of the red column, both the square and the column will be satisfied. However without more information we do not know which row will be satisfied along with this criteria. Therefore we cannot place 7 with certainty. Hard Killer Sudoku levels have the same rules as any other level, the only difference is very few numbers on the grid from the beginning. This makes the game pretty hardcore and requires longer playing time to fill out all the numbers. It’s definitely a great fit for players who have had enough of the classic sudoku and want to step up their game. “Minimum and Maximum” strategy

Super Hard Sudoku and the "Sudoku Master" series (Magworks Australia): I recommend these booklets for people who really want a real sudoku challenge. These booklets start with puzzles that many newspapers rate Diabolical or Evil and it ramps up from there. You should find an X-wing in the starting puzzles. Most of the time if this is not required, then I find the sudoku trivial. Eventually you need Y-wings, Chains, Nice Loops, and Unique Rectangles to unravel the puzzles. Some of their puzzles were wonky when they started publishing ... with one having 28 solutions but I think they have gotten their act together with later issues.

Now you try! See if you can deduce what number goes in the red slot. Solve the blue square by using the surrounding squares to find you answer. Nikoli's hand-made Sudoku puzzles first appeared in Japan, about 20 years ago. Puzzler Media met Nikoli at the World Puzzle Championship in Arnhem in 2003 and were introduced to Sudoku there. We published a few puzzles in our titles, but things didn't take off until a Japanese puzzle enthusiast called Wayne Gould (who, in his spare time, had devised a computer program to generate Sudoku) walked into 'The Times' offices in London, in the Autumn of 2005, to demonstrate the program.

Sudoku is a type of logic puzzle that requires you to fill in digits on a 9x9 grid. The grid starts out with some positions populated and your job is to fill in the remainder. The numbers must meet certain criteria, specifically that the same digit cannot occur more than once in any column or more than once in any row. Additionally, you'll notice the sudoku grid is divided into 9 squares, each 3x3, and a digit can also only occur within these squares.

By eliminating everything that will not fit, we find that we are left with one number with no objections and that meets all three criteria. In Japan, word-based puzzles were hampered by the complexities of a language that combined different scripts (kanji, hiragana, katakana, plus a dash of rõmaji). This provided an opportunity for puzzles deploying the Western-style Arabic numerals that were generally in use to represent numbers. But the truth is, we all forget things from time to time — and memory loss is not inevitable as we age. In recent years, neuroscientists have discovered that the brain can remain much more robust over time than they once thought. We will be using some different techniques to solve puzzles at all levels. This guide will take you from the bare basics to mastering the hardest puzzles. You’ll have the chance to slowly learn all the skills and test them all in the end! Having a social conversation is a complex mental task: We must listen, remember what the other person has said, think of what we want to say next, and pay attention to nonverbal and emotional cues. Talking is such an effective brain-booster that one study at the University of Michigan saw improved working memory among subjects who engaged in a single 10-minute conversation. 4) Learn something new.