## Sudoku without numbers

Everything about Sudoku that doesn't fit in one of the other sections

### Sudoku without numbers

I've come across Sudoku variations which use things like shapes or faces instead of numbers, but i've never been able to solve them as effectively as the numbered versions...

Is this simply a matter of getting used to, or is there some deeper psychological reason?
Alk

Posts: 2
Joined: 26 February 2006

It's a matter of getting used to them. The trouble is that you have spent almost your entire life getting used to the digits so you can rapidly recognize them as a set and deduce which ones are missing.

If there were another set of nine which you were as familiar with you would probably find Sudoku just as easy with them.

I wonder if astronomers would find "Planet" Sudoku easy!
EricK

Posts: 4
Joined: 19 January 2006

One possibility: with numbers you already have a verbal label to refer to. with pictures you have to make your own label which increases the computing time required by the brain. if you used one set of symbols repeatedly presumably this factor would disappear.

One way to test this might be to try solving a sudoku with some other familiar symbols that you already have verbal labels for, for instance letters, and seeing if that affects your solving ability. Or maybe pictures that it's very easy to produce verbal labels for, such as the dots on dice or dominoes.
ab

Posts: 451
Joined: 06 September 2005

I think it also helps a bit that there's an obvious order to go through the numbers in, so when you're counting off what's already in a row, you can go through them 1, 2, 3... . The same applies to letters (though it would be less easy if the leters were, say, CFGKLOSUZ instead of ABCDEFGHI), but with nine abstract symbols, you probably will have to make and remember an arbitraty ordering for yourself.
PaulIQ164

Posts: 533
Joined: 16 July 2005