Combine oats, flour, sugar, soda and salt. Cut in the shortening with a pastry blender or 2 knives until the mixture is crumbly. Using a fork, gradually add enough water for moisture to form a ball. Roll out 1/4" thick on a lightly floured board. Cut into circles and place on greased baking sheet. Bake at 350F for 15 minutes. Yield about 4 dozen, depending on spoon size.