Place the ruler
Cut along the ruler
Rotate the cutting board (not the block) 90 degrees and repeat the cut.
Rotate and cut
Repeat this twice more until you have cut all around the centre. You will have 9 separate pieces.
4 cuts, 9 pieces
Pick up and rotate the middle strip on the bottom line and replace it so that the light fabric lies next to the dark, and the dark lies next to the light.
Rotate the 2-coloured strip
Light to dark