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.
(In reply to Diagonals
The dots in the diagonals are entirely brianjn's idea, so all credit for this must go to him. This very effective reminder first appeared in Killer-X-tra pid=6077.
Thanks for your encouraging words about my puzzles! :) It's amazing how I am spurred by such comments! Last night, I sat making a "double knight's tour". Half of it is thoroughly checked, but I need to to check the other half.
After walking the dog, we are going shopping for outfits for our visit to Oz, but this evening is (as yet) untouched!
Take care yourself and enjoy your day!