Sensory bins seem to be at an all time high right now....and for good reason. There are so many teaching possibilities. For this one, we were learning about the ocean. Easy enough. You can make the foam with equal parts dawn dish soap and water....for the extra fluff add 1/2 cup of cornstarch. We added a few drops of liquid watercolors to make it the pretty blue. We had a few fish and sharks to add, along with some seashells. Orbeez are another great add on.
After our bubbles ran out we moved onto watercolors. Easy enough to find seashell printable online or in coloring books.