Dinosaur week: Fun & Simple dinosaur activity for kids! Maybe for older kids give each shape a numerical value and have them add how much their dino is worth. Can use with class to compare/contrast amounts, etc.
Easy kiddie kitchen sinks: find a table, cut two holes, insert plastic tubs - can't find this on the link but the picture pretty much tells you what to do! Great idea for outdoor play space In the summer
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!