These plastic white trays are invaluable in your science center. Use these trays in your science center or throughout your classroom. You can draw on the trays and use them for sorting the Fun Science Sorting bugs or place one of the trays under the Fun Science Folding Magnifier to hold the objects you are observing. The possibilities are endless for these trays. The White Tray 4 Pack is a great addition to your Science Accessories section of your Science Center (4 white trays in the set, critters not included).Scientific Skills: Measuring, Sorting, Exploring, and Investigating.