Overview
Number-pattern
problems similar to our digi-clues are a standard
part of many intelligence test batteries (e.g., the
Stanford-Binet Number Series section). Number series
with implicit patterns are also one of the things
included in attempts (in real science fiction) to
communicate with extra-terrestrial life. It's assumed
that any truly intelligent being, human or not, will
be able to decipher them.
How
to Begin
The
most straightforward puzzles of this type present you
with a series of numbers that have a single regular relationship
between them. For example:
1 2 4 8
...
or
1 5 9 13
...
You
can continue the first series simply by doubling each
number as you go along; the second, by adding 4 to each
number. What makes these easy is that each number in
the series is the result of a single simple mathematical
operation performed on the previous one, resulting in
a transparently regular pattern.
Now
take a look at this:
7 2 8 6 4
3 3 5 2 8
5 9 1 5 8
1 8 7 1 ?
Even
with three rows of numbers to help you deduce the pattern,
this is harder because there's no simple, transparent
relationship between the individual numbers. Once you
group some of the numbers into two-digit pairs, the problem
becomes absurdly easy; the pattern can be illustrated
as follows:
72
- 8 = 64
So,
the missing number on the fourth line is 1. The leap
of insight leading you to combine numbers into two-digit
pairs requires a little more than just finding a regular
pattern between individual one-digit numbers.
The
more kinds of operations involved (addition, division,
etc.), the more challenging the puzzle will be to solve.
Take a look at this one:
37 15 26
83 71 77
12 186 99
52 18 ?
The
job of combining single numbers into multiple-digit numbers
is already done for you. But again, if you're looking
for a single constant relationship between adjacent numbers
in the series, you'll fail to find it.
The
solution? For each line, just add the first two numbers
together, and the third number is half that total. The
missing number on the fourth line, then, is 35. Once
you see the pattern, the puzzle seems ludicrously simple.
The fact, however, that you have to do two things to
the first two numbers - add and then divide by two -
to get the third obscures the pattern and makes the puzzle
harder.
Also
tricky are puzzles where a number that isn't even shown
in the series provides the key to the solution. Here's
an example:
36 18 19
22 70 77
7 9 1
100 50 ?
What's
the pattern? If you add the first two numbers together,
and subtract the third from the sum, you'll always get
15. Once someone tells you, you'll slap your hand to
your forehead, but there are two things that make the
pattern hard to find. First, there are two operations
involved. Second, you have to come up with a fourth number,
in addition to the operations, to make sense of the series.
But patterns that are hard to find are also more rewarding
once you find them.
One
final tip: Sometimes, the pattern may lie vertically,
not (or not just) horizontally.
Beware
of Experimenting
with Random 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 digi-clue 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 link. But if you're having
difficulty getting started, HELP #1 contains clues
to the correct words and HELP #2 gives the correct
answer to one of the anagrams.
