Place the numbers 1 to 9 once in each row, column, long diagonal and 3x3 box. Obviously, the central yellow-coloured 3x3 box is common to both grids.

The number in the cage (or shaded area) represents the result of an arithmetical operation by its accompanying sign. For example, 4÷ in a two-celled cage means that it contains either 8 and 2 or 4 and 1 (in any order).

Unlike Killer Sudoku, the same number may appear more than once in a cage. So, 28x in a cage which overlaps the 3x3 grids may contain two 2s and a 7.

Once again, I wish to thank brianjn most sincerely for his continued support. He converted my black and white Excel image to a coloured one in 'jpg' format.
Acknowledgement to Peter at sudexel.com for beta testing the puzzle.

Second, here is a hint:

 

I focussed on the digits 5 and 7 heavily.  This is because if a cage's product has 5 or 7 as a factor, then it must have 5 or 7 as one of the digits in a cell.  This is because they are prime numbers (so they can't be reduced to any smaller factors) and any multiple of 5 or 7 will be greater than 9.

Edited on June 24, 2008, 1:55 am

Posted by nikki on 2008-06-24 01:20:16