Hidato

Hidato is another math logic puzzle which is similar to sudoku, but different enough to be fresh and new. It also known as Number Snake, Snakepit, Jadium and Numbrix.

The goal of hidato is to complete the grid with numbers in consecutive order going horizontally, vertically, or diagonally. 

The smallest and the highest numbers are always shown on the hidato grid, represented by a circle.  So in the example below, 1 is the lowest number in the puzzle, and 19 is the highest number.  

Uncompleted Hidato Grid

Each of the cells contains a number between 1 and 19.  Some of the answers are already given.  To complete the grid, determine what number belongs in the blank cells, keeping in mind that a number must be adjacent either horizontally, vertically or diagonally to its next and previous consecutive number.

So in the example given above, when determining where to place the number ‘2’, remember that it must be placed in a cell adjacent to both the number 1 and the number 3.  Therefore, there is only 1 possible cell:

Partially Completed Hidato Grid

Now we just fill in the rest of the cells using the same logic.  Give it a try…and then compare your grid to the solution below:

Completed Hidato Grid

Not complicated, but these can get tricky!  Even a small grid can be tough puzzle to crack.  But as with all logic puzzles, they help improve focus, reasoning skills, flexibility, patience, and of course, they are fun.

Try some hidato puzzles in your local newspaper, or you can find some great hidato puzzle books online.

Happy puzzling!

The Logic Puzzler

KenKen

KenKen?  Who is he? 

Actually, KenKen (aka KenDoku, MathDoku or CalcuDoku) is a great new math logic puzzle that is quickly growing in popularity.  

KenKen is similar to Sudoku, but with an added twist, so you get to think and use your brain in a slightly different way.

So how do you play?  Let’s look at the example below:

Uncompleted KenKen Grid

Like Sudoku, you need to fill the KenKen grid with digits, but you must use the following rules:

• The digits that go in the grid correspond to the number of rows/columns, e.g. 1-3 for a 3 x 3 grid, 1-4 for a 4 x 4 grid, etc.
• No digit is allowed to appear more than once in any row or any column
• The bolded groups of cells is called a cage; the digits that go in each cage must equal the number at the top left of each cage when you apply the mathematical symbol at the top left of the cage
• Digits may be repeated within a cage, as long as they are not in the same row or column

In the example KenKen grid given above, the grid is 3 x 3, so only the digits 1, 2 and 3 can be used.  We know the digit in the upper right cell is 2, because the number in the top left of the 1-cell cage tells us that.  The first cage has “2-” at the top left, so the digits for that cage must equal 2 when you subtract one from the other.  So the only possible solutions for the first cage is 1, 3 and 3, 1 (3 – 1 = 2).  Now we need to use the clues in the other cages to help us figure out if it should be 1, 3 or 3, 1, keeping in mind that the same number cannot appear in any row or column.

Partially Completed KenKen Grid

Can you determine the digits that go in the remaining cells?  Here is the solution.

Completed KenKen Grid

Et voila!  The puzzles increase in difficulty as the size of the grid increases.  But with practice, you can be completing 10 x 10 KenKen puzzles in no time!  They are a great alternative when you get tired of Sudoku and need something new and challenging.

KenKen puzzles are becoming more and more common in newspaper puzzle sections around the world, but if your local paper does not have it, or if you need more than just 1 per week (like me!), you can get KenKen puzzle books here. (Note: KenKen is a trademarked name, so you might find these puzzles under the generic names MathDoku or CalcuDoku.)

As always, happy puzzling!

The Logic Puzzler

Prismapixels

Prismapixels could be explained as logic puzzles on acid.  But I prefer to think of them as coloring books taken to the next level.

Prismapixels are like nonograms, (aka picross, griddlers, and o’ekaki).  If you are not sure what these are, you can read about nonograms here.

A prismapixel is a nonogram but with the added depth of using color.  They are solved in the exact same manner, but your finished work of art is now in color.

Here is a very simple example of a prismapixel grid, ready to be solved:

Prismapixel ready to be completed

The rules for solving are the same as a nonogram.  If you have forgotten what those rules are…

1. The numbers on the left of each row and the top of each column represent the lengths of consecutive colored cells.
2. The colored cell blocks occur in the same order as the numbers.
3. There is at least one blank cell between two colored cell blocks

Like nonograms, solving prismapixels is tricky, but still definitely doable.  My trick is to start with a pencil, and in each square, put a letter that corresponds to the correct color for that square.  That way, I can still erase and make corrections, before completing the puzzle with colored markers or pencil crayons.

Solving prismapixels is so much more rewarding than completing a coloring book page, because you are not only stimulating your artistic side, you are strengthening your cognitive skills at the same time.  And the result is just as rewarding as coloring, as you can see by this beautifully completed puzzle below.

Completed prismapixel puzzle courtesy of wired.com

The other thing prismapixels have in common with nonograms is that that they are just as difficult to find at your local bookstore.  But I have found some great ones on Amazon and Etsy that you can easily get. 

Happy puzzling!

The Logic Puzzler