Small hands will be drawn to these satisfyingly smooth and tactile natural sorting stones, which are large enough to be safe for your youngest learners.In four earthy colors and three different sizes, they invite sorting, stacking and exploration of pattern and sequence.A great resource to help young children develop early math concepts through exploratory play.Natural Sorting Stones are ideal for sensoryplay activities and are durable enough for use in sand, water and the outdoors.Each set includes 12 stones in three different sizes (23) and four natural colors.Correlation to Common Core: K.MD.B.3.Correlation to ECERSR: LanguageReasoning 16, 17, Activities 19, 23, 26.Correlation to ITERSR: Activities 15, 21.