Here's a set of mats to use in your Sensory Center or PlayDough Center. I spray painted glass gems and labeled them with upper case & lower case letters and numbers 0-20. Then I hid the rocks in my Sensory Table (I hid them in rice, but you could use sand, corn, water, or any number of other materials!). As the children found the gold, they matched them to the mats. The mats are differentiated so you can use the ones best suited to your students' needs.
The pots of gold are playdough mats. The students create "gold pieces" to match the number on each pot.