Sudoku building block template

I came across a discussion about icebreaker exercises and one of the ideas was to add a sudoku puzzle to the mural to keep participants busy if they have completed an exercise whilst others are still working. I created a building block template of an empty sudoku puzzle. Search on the internet for puzzle examples to fill in. The building blocks used for this was a 3x3 matrix (from the icons library), square notes all embedded in an area with instructions on the outline.