How To Solve Kakuro

Transcription

1

2 THE RULES Each row must contain each number from to 9 Each column must contain each number from to 9 Each box (small by grid shown by thicker lines) must contain each number from to 9 THIS MEANS THAT EACH NUMBER SHOULD ONLY APPEAR ONCE IN EACH ROW, COLUMN AND BOX! TOP TIPS FOR SOLVING SU DOKU Pencil in maybes In Su Doku you cannot guess! You must use logic to check all possibilities and be certain before you enter a number. It can help to put in little maybe numbers in your grid whilst you check all the possibilities. 5 Slicing and Dicing Number Pairs If you have a pair of numbers it can help find the third one. In this example you can see there is a in the middle row, a in the bottom row so we need to find a in the top row. You know it cannot go in the left box because it has a, it cannot go in the middle box because it has a so it must be in the right hand box in the top row. You have now narrowed it down to two maybe positions shown by the arrows! 2

3 Now from your two maybe positions, you can look down the columns for clues. You can see there is a number in this column already. This mean it must go in the left hand maybe. So now you are certain (remember no guessing!), you can rub out your maybe numbers and put in your bigger in this box. Once you have worked out the whole grid using this method, you can work across and do the same thing. Slice across Dice downwards! Fill in the gaps Remember the basic rule, each line must contain each number from to 9. If you have a line, column or box with only a few empty spaces you can put in the numbers you are missing as maybe numbers and look for clues around it. Some Weblinks for Sudoku A flash player to generate puzzles at ten levels of difficulties: A player to download to generate many puzzles to solve: 00 Sudoku puzzles to download and print: An online games with easy, medium and hard puzzles: An online puzzle player Three puzzles to solve different every day: The Times Su Doku page:

4 Hot on the heels of Sudoku comes Kakuro. Think of them as the mathematical equivalent of crosswords. They are also known as Cross Sums or Kakro in Japan. A Kakuro consists of a playing area of filled and empty cells similar to a crossword puzzle. Some black cells contain a diagonal slash from top left to bottom right with numbers in them, called the clues. A number in the top right corner relates to an across clue and one in the bottom left a down clue. RULES You must fill all the empty spaces with digits from to 9. The numbers must add up to the clue at the end of the row. Each number in a combination must be different. Sound simple? Be warned it gets hard and is as addictive as Sudoku!! TOP TIPS FOR SOLVING KAKURO Kakuro is all about combinations. Which combination of numbers can add up to your clue total. It is similar to Sudoku as you cannot guess, you must use logic. UNIQUE SETS There are some totals which can only have one combination of numbers. If you saw the sum + the boxes are ( and 2). If you saw the sum + and 7) or ( and 6) or (4 and 5). =, the only numbers which can go in = 9, the answer could be ( and 8) or (2 This means that a total of with 2 boxes has a unique set of numbers. It can only be one combination. A total of 9 with 2 boxes is not unique because it has lots of answers.

5 Use your Kakuro helper sheet. It shows all the totals which are unique. A good starting point is to look for totals which have a unique set of numbers. If you look at the corners of the puzzle you will often find these. Look up the numbers in your table and find out the combinations for these totals. You can now start to enter maybe numbers just like Sudoku. 2 2 COMBINATION CROSSINGS This is known as cross sums because the combinations cross over each other. 4 4 Look for a common number which is in both sets for the number box where the combinations meet. Number is in both so that must be the number where the lines cross. 4 If you look at this puzzle, you have: a clue total of 4 with two boxes a clue total of with two boxes From your unique sets you know that: must be and 2 4 must be and 2 From this you can work out the other numbers. A total of 4 is + A total of is + 2 Once you fill in all your unique numbers it will give you lots of clues for filling in the rest of the puzzle

6 MAXIMUM AND MINIMUM NUMBERS 9 If you look at this puzzle on the left there are two totals. When a total of with 2 boxes you know it must be and 2 so you can put in some maybes. 2 2 A total of 9 with boxes is not unique but it can help us decide which of our maybes is correct! Here are the minimum and maximum totals you can have for each length. A length of Minimum Maximum 2 (+2) 7 (8+9) 6 (+2+) 24 (7+8+9) 4 0 (+2++4) 0 ( ) 5 5 ( ) 5 ( ) 6 2 ( ) 9 ( ) 7 28 ( ) 42( ) 8 6 ( ) 44 ( ) 9 45 ( ) 45 ( ) 9 If you look at a length of 2 boxes the maximum total is 7 made up of 8 and 9. This can help you decide on our maybe and 2 possibilities. This can get quite confusing though! Look at this box. It can either be a or a 2. If it were, the other 2 boxes would need to total 8 because all three must total 9. We know that you can not make a total of 8 with two boxes because the maximum total you can have is 7. This means it must be 2 in this box. You can then put in your maybe possibilities for the other boxes. THE MORE YOU PLAY KAKURO, THE EASIER IT GETS! YOU WILL LEARN THE UNIQUE SETS TO LOOK OUT FOR AND WORK OUT YOUR OWN STRATEGIES.

7 Length Smallest Largest HUNGRY FOR MORE? Lots of puzzles at different levels with tips for beginners. Daily puzzle plus an archive of hundreds. Puzzles to print or play online. A brillinat site which includes a trial game player to download.