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by:  Erik Oosterwal

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Really, Really, Really Big Numbers - Solution

Using the most common mathematical operations, the biggest numbers you can make using only four 1's and four 2's are:

1111 = 285311670611

2222 = Some number with a million digits in it.



There is another less well known mathematical operation called tetration, also called iterated exponentiation or hyperpower, which takes exponentiation to the next level.  Just like 1111 is shorthand for multiplying 11 by itself 11 times (11•11•11•11•11•11•11•11•11•11•11), 1111 is shorthand for 11^(11^(11^(11^(11^(11^(11^(11^(11^(1111))))))))). My calculator is capable of handling numbers up to 1•10500-1, and it blew up after the second iteration of exponentiation.  Since googol is 1•10100 and googolplex is 1•10^(1•10100), you can just imagine how big of a number 1111 is.

I can't wrap my head around a number that big and 2222 is multiples of magnitudes larger than that.  Those are some really, really, really big numbers.


Of course we could get even more silly and bring up a couple of other lesser known operations called Pentation and Hexation.  Just like Multiplication is a repeated addition, Exponentiation is a repeated multiplication, and Tetration is repeated Exponentiation, Pentation is defined as repeated Tetration and Hexation is defined as repeated Pentation.  At this point the numbers get so humongously large that they stop having any real useful purpose.

Incidentally, you can write the various math methods like this:

Multiplication: x*y, which means x added to itself y times.
Exponentiation: x**y, which means x multiplied to itself y times.
Tetration: x***y, which means x exponentiated to itself y times.
Pentation: x****y, which means x tetrated to itself y times.
Hexation: x*****y, which means x pentated to itself y times.



All original puzzles and solutions are © Erik Oosterwal 1993-2008

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