Had when i worked in a preschool and kids love them! I would use colored sand instead of white salt. DIY salt tray with alphabet cards. Easy to make and kids have fun smoothing out the salt after correctly making the letter
How to Make a Leak Proof Water Blob (without tape! We did a blob last year. The kids loved it. And it leaked. I looked over how she does it (iron-genius! We added glitter to our water to make it a little more fun.