The Ultimate Guide to Hands On Toddler Activities - Brittany Estes--- This could also work for pre-math skills. Which shape has more or less? I would put on magnets on the back and have a magnetic work space for them to do this activity!
Play Create Explore: Baby Oil Sensory Bags = baby oil, food colouring, a little bit of water, glitter, objects to find (smooth). Put in ziplock bag and duct tape for leaks and little fingers who would like to open it. ((or a heat seal bag))