>Hi everyone,
>
>I'd like to convert numbers to the following:
>
>5->5
>52->50
>333->300
>4567->5000
>1234567->1000000, e.g. to the round number.
>
>What would be the simplest algorithm for this?

?ROUND(x, -INT(LOG10(x)))

For negative numbers, slightly more complicated:

?ROUND(x, -INT(LOG10(ABS(x))))

Works for numbers not between -1 and 1... for them, then, it would need a +1 decimal more.