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How to Play Addlocks

Overview
Addlocks are a lot like regular crossword puzzles, except that both the clues and the answers are numbers rather than words. As with crossword puzzles, the interesting format makes it both harder and easier to come up with a correct answer. It's harder because not just any old answer of the right length will do, since intersecting answers must match. But it's also easier, since the answer to an easy clue will help you figure out a more difficult intersecting one.

How to Begin

For every addlock puzzle, there are some fixed rules. Zero is never allowed. No number is ever used twice in any single answer. For example, let's say you're trying to solve 1 Across:

 

 

1 Across has two spaces, so you need two numbers that will add up to 6. In theory, there are seven possible answers: 0-6, 1-5, 2-4, 3-3, 4-2, 5-1, and 6-0. But since zero isn't allowed, you can eliminate the first and last. And since you can't have two of the same numbers in one answer, you can eliminate 3-3. That leaves you with 1-5, 2-4, 4-2, and 5-1.

 

Sometimes you'll be given extra clues such as that a given number other than zero is never allowed. Also, we might tell you that all the answers end in an odd number, or even number. These are important clues that will help you narrow down the field of possible answers.

 

Taking another look at our example, let's say we told you that 8 is never allowed in this puzzle and all answers must end in an even number. The even-number clue rules out 1-5 and 5-1, leaving 2-4 and 4-2. Now, look at 2 Down (clue: "10"). If the answer for 2 Down began with 2, then the second number would have to be 8, which is not allowed. So you know 1 Across must be 2-4, and 2 Down must be 4-6. One answer leads to another, and you're on your way.

 

Since short answers are easier to solve than long ones, it's usually good to start short and work your way to long ones from there. If you look at 3 Across, a 3-number row, you'll see that the answer to 2 Down gives you the first number in  3 Across's solution. To see how easy it is to get the answer with that head start, take a moment to figure out the other possible numbers that will add up to the number given in the clue, "19". The 6 you already have tells you that you need two more numbers that must add up to 13: 9-4, 8-5, 7-6, 6-7, 5-8, or 4-9. Since 8 is not allowed and you can't have two 6's in one row, you're left with the first and last options, and since the row must end in an even number, you know only the first can be right. So of all possible three-number series that could add up to 19, you've singled out the only possible correct answer.

 

 

Beware of Experimenting with
Random Number Combinations
Mistakes can be costly because elapsed time is key to your score. If you enter two wrong numbers in any one square, that square will lock until a correct number is placed in another square in the grid. You can disable this 2-tries lockout by checking the box located in the puzzle.

Scoring
A timing clock starts automatically when you enter your first number into the game-grid. It runs until you have entered a correct number into each of the spaces in the game-grid. Your score will show the ratio of total correct responses to total possible responses. It will also show your total elapsed time.

Select Your Own Difficulty Levels
Each addlocks is given a Brain-Gain Level of 1 (easiest), 2 (medium), or 3 (hardest). Click on one of these links to try games at the level you like. To make any game more difficult, try not to look at the Help links. But if you're having difficulty getting started, HELP #1 contains clues to the correct numbers and HELP #2 gives the correct answer to one of the anagrams.

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